THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 


LIBRARY, 

ANGELES,  CALIF. 


U.  S.  DEPARTMENT  OF  AGRICULTURE 

DIVISION  OF  BOTANY. 

BULLETIN    No.    12. 


GRASSES  OF  THE  SODTIIWEST, 


PLATES  AND  DESCRIPTIONS 


GRASSES  OF  THE  DESERT  REGION  OF  WESTERN  TEXAS,  NEW  MEXICO, 
ARIZONA,. AND  SOUTHERN  CALIFORNIA. 


Part   I. 


By  DR.  GEO.  VASEY, 

BOTANIST,    DEPARTMENT   OF    AGRICULTURE. 


ISSUED  ,*5CT<MH&ft  ,f  $,i 


PUBLISHED  BY  AUTHORITY  OF  THE  SECRETARY  OF  AGRICULTURE. 


WASHINGTON: 

GOVERNMENT   PRINTING   OFFICE 

1890. 


NOTE. 

This  Bulletin  is  to  constitute  the  first  half  of  the  first  volume  of  a  work 
entitled  "  Illustrations  of  North  American  Grasses."  The  work  when  completed 
will  consist  of  two  volumes,  the  first  entitled  "Grasses  of  the  Southwest,"  the 
second,  "Grasses  of  the  Pacific  Si  ope."  Proper  title-pages  and  indexes  will  be 
published  with  the  last  part  of  each  volume. 
2 


v,t-; 

* 


LETTER    OF    TRANSMITTAL. 


WASHINGTON,  Jime  5,  1890. 

SIR  :  I  have  the  honor  of  presenting  for  publication  the  manuscript  of  a  Bulletin 
on  the  Grasses  of  the  Southwest. 
Respectfully, 

GEORGE  VASEY, 

Botanist. 
Hon.  J.  M.  RUSK, 

Secretary  of  Agriculture, 

3 


INTRODUCTION 


The  region  of  country  immediately  ad  joining  the  northern  boundary  of  Mexico, 
including  the  western  part  of  Texas,  and  the  greater  part  of  New  Mexico,  Arizona, 
and  southern  California,  is  one  of  remarkable  heat  and  aridity.  It  is  mainly  a 
region  of  elevated  plains,  called  mesas,  intersected  by  mountain  ranges  which  occa- 
sionally run  into  high  peaks,  and  is  drained  by  comparatively  few  streams,  which, 
on  account  of  the  limited  rain-fall,  cease  to  flow  during  a  good  part  of  the  year,  or 
convey  only  the  waters  obtained  from  distant  portions  of  the  country. 

Most  of  the  region  lies  north  of  the  thirty-second  parallel  of  latitude,  and  in  the 
western  part  reaches  into  Utah  and  Nevada.  It  is  with  great  propriety  called  the 
desert  belt.  The  country  northward,  and  east  of  the  Rocky  Mountains,  as  far  as 
the  one  hundredth  meridian,  is  an  elevated  arid  plain,  but  with  more  abundant 
grasses,  although  rarely  forming  a  continuous  and  connected  sod. 

In  the  desert  belt,  however,  the  grasses  become  scanty,  not  in  variety  of  species, 
but  in  distribution,  some  of  them  being  short-lived,  springing  up  suddenly  after  the 
summer  rains  and  rapidly  maturing  ;  others  perennial,  growing  in  bunches,  and 
having  deeply  penetrating  roots  which  enable  them  to  endure  the  long  droughts  of 
the  country.  Nowhere  do  the  native  grasses  form  a  continuous  sod,  but  grow  in 
scattered  bunches  in  connection  with  the  low  bushes  which  prevail  on  the  mesas  or 
among  the  chaparral. 

The  country  embraced  in  this  desert  belt  is  an  extension  northward  of  the 
great  plateau  of  northern  Mexico,  as  is  shown  in  the  similar  character  of  its  vege- 
tation. The  grasses  are  largely  the  same,  or  of  the  same  genera.  But  the  grasses, 
like  the  rest  of  the  vegetation,  are  peculiar  to  the  region.  Here  one  never  sees  the 
common  grasses  of  the  Eastern  States.  The  vegetation  is  as  different  from  that 
of  the  Eastern  States  as  is  that  of  the  northern  portion  of  the  Sahara.  Hence 
arises  the  utility  of  bringing  to  the  notice  of  the  public,  and  especially  of  the 
residents  of  this  region,  the  information  contained  in  this  work.  It  is  not  a  manual 
or  description  of  all  the  grasses  of  the  region,  but  it  furnishes  illustrations  and  de- 
scriptions of  some  of  the  more  interesting  and  some  of  the  commoner  grasses  of  the 
country.  Many  of  them  were  observed  and  specimens  collected  by  the  naturalists 
of  the  Mexican  Boundary  Survey,  and  by  those  of  the  Pacific  Railroad  Survey,  but 
few  or  none  of  these  have  heretofore  been  illustrated  or  fully  described.  True,  the 
descriptions  here  given  are  mostly  in  technical  language,  but  accompanied  by  the 
illustrations  they  afford  the  best  possible  means  of  recognition.  Probably  the  most 
important  agricultural  question  before  the  people  of  this  region  is  how  to  increase 
the  production  of  grasses  and  forage  plants  on  the  arid  lands.  It  is  the  opinion  of 
many  that  this  can  be  done  by  bringing  under  cultivation  some  of  the  native  species. 
Experiments  are  about  to  be  undertaken  in  this  direction  by  the  Agricultural  Ex- 
periment Stations  and  by  individuals.  The  first  step  in  such  an  enterprise  is  a 
knowledge  of  or  an  acquaintance  with  the  native  species.  Nothing  can  be  better 
adapted  to  this  object  than  the  work  here  undertaken,  and  in  this  way  the  knowl- 
edge of  the  scientist  can  be  made  helpful  to  the  practical  economist.  In  this  first 
part  of  the  work  fifty  plates  of  grasses  are  given.  A  second  part  of  an  equal  num- 
ber of  plates  is  now  in  preparation,  after  which  it  is  proposed  to  publish  an  analyti- 
cal synopsis  of  all  the  grasses  of  the  desert  region.  The  drawings  of  the  grasses 
have  been  made  chiefly  by  Mr.  William  R.  Scholl,  and  in  the  description  of  the 
species  I  wish  to  acknowledge  important  aid  from  Mr.  Frederick  V.  Coville,  Assist- 
ant Botanist. 

5 


INDEX  OF  PLATES. 


Plate. 

^Egopogon  gerniniflorus 12 

Andropogon  cirrhatus 18 

hirtiflorus 19 

saccharoides 20 

Wrightii 21 

Aristida  Arizonica 22 

divaricata 23 

Bouteloua  arenosa 34 

aristidoides 35 

Burkei '. 36 

eriopoda 37 

Havardii 38 

hirsuta 39 

Humboldtiana : 40 

oligostachya 41 

prostrata 42 

racemosa 43 

ramosa 44 

stricta 45 

trifida '. 46 

Buchloe  dactyloides 47 

Cathestecum  erecturn 13 

Cenchrus  myosuroides 6 

tribuloides. ; 7 

Chloris  alba 29 

ciliata 30 

cucullata 31 

glauca 32 

verticillata 33 

Elionurus  barbiculmis 15 

Epicampes  macroura 27 

rigens...... .. 28 

Eremochloe'Bigelovii 48 

Kingii •.  48 

Eriochloa  sericea 1 

Heteropogon  contortus 16 

Hilaria  cenchroides 10 

mutica 11 

Melica  diffusa 49 

Porteri 50 

Muhlenbergia  distichophylla 25 

gracilis 26 

Panicum  bulbosum 2 

ciliatissimum 3 

lachnanthum 4 

Setaria  caudata 5 

Stenotaphruin  Americanum 8 

Stipa  flexuosa 24 

Thurberia  Arkansana 9 

Trachypogon  polymorphus 17 

Tragus  racemosus 14 

7 


GRASSES  OF  THE  SOUTHWEST. 


No.  1. 
ERIOCHLOA  SERICEA  Munro. 

Roots  long,  unbranched,  but  giving  off  a  few  fibrillee. 

Culms  tufted,  simple,  i  to  3  feet  high,  stiffly  erect,  slender,  striate,  short- 
villous  at  the  nodes  and  sparingly  minutely  hairy  where  not  sheathed. 

Radical  leaves  numerous,  6  to  12  inches  long,  erect,  flat  or  involute,  striate, 
minutely  pubescent  or  glabrous,  |  to  1  line  broad,  the  sheaths  free.  Cauline 
leaves  3  or  4;  sheaths  contiguous  or  nearly  so,  striate,  minutely  pubescent  or  gla- 
brous, villous  at  the  apex;  ligule  a  row  of  dense  straight  hairs;  blades  like 
those  of  the  root-leaves,  spreading,  3  to  9  inches  long,  uppermost  often  shorter. 

Inflorescence  a  racemose  compound  spike,  the  peduncle  usually  exserted  from 
the  uppermost  sheath;  axis  minutely  pubescent;  spikes  4  to  7,  sessile  or  the  lower 
short-peduncled,  erect,  contiguous,  or  nearly  so,  f  to  l£  inches  long. 

Spikelets  elliptical-oblong,  acute,  depressed,  1|  to  2  lines  long,  imbricated  (one- 
half  their  length)  in  2  rows  along  the  outer  side  of  the  flat  rachis  of  the  spike, 
each  sessile  on  an  annular  swelling  of  the  apex  of  a  short,  long- villous  pedicel 
(about  as  broad  as  long),  hairs  equaling  the  spikelet. 

Glumes  3;  outer  2  equal,  membranaceous,  inclosing  the  rest  of  the  spikelet, 
ovate,  oblong,  acute,  5-nerved,  villous  without;  flowering  glume  glabrous,  thick- 
ened-coriaceous,  minutely  rugose,  elliptical-oblong  and  acute,  rounded  on  the 
back. 

Flower  single,  hermaphrodite.  Palet  similar  in  texture  to  the  flowering 
glume,  2-nerved,  flat  on  the  back.  Stamens  3,  the  anthers  two-thirds  as  long  as 
the  palet.  Stigmas  2,  fimbriate,  purple,  nearly  one-half  the  length  of  the  palet, 
on  slender  styles. 

PLATE  I;  a,  spikelet  opened  so  as  to  show  the  glumes,  palet,  pistil,  and  sta- 
mens. In  the  figure  the  flowering  glume  is  too  much  narrowed  toward  the  apex, 
the  palet  is  not  represented  as  flat  on  the  back,  and  the  stigmas  and  anthers  are 
too  short. 

This  species  seems  to  be  principally  confined  to  western  Texas  and  New  Mex- 
ico, extending  northward  into  the  Indian  Territory.  It  affords  a  considerable 
quantity  of  foliage,  is  perennial,  and  should  be  tried  with  reference  to  its  agri- 
cultural value. 


n 


^, 


ERIOCHLOA  SERICEA,  Munro. 


No.  2. 
PANICUM   BULBOSUM  H.  B.  K. 

Rootstock  creeping,  slightly  branching,  the  yearly  growth  short  (commonly 
i  inch) ,  base  of  the  culm  becoming  enlarged  into  a  corm  f  to  f  inch  long,  or  some- 
times nearly  wanting.  Roots  simple,  strong. 

Culms  erect,  single  or  few  together  in  a  loose  clump,  slender  or  stout  (some- 
times i  inch  thick),  simple,  glabrous,  glaucous  at  the  nodes. 

Leaves  with  striate  blades  1  to  4  lines  broad.  Radical  few,  commonly  1  to  2 
feet  long;  sheath  elongated,  loose,  glabrous  or  the  margins  sometimes  ciliate;  blade 
glabrous  or  very  sparingly  hirsute  at  the  base,  slender-acuminate  at  the  apex; 
ligule  short,  fimbriate.  Sheaths  of  the  stem  2  to  4,  not  contiguous,  sheathing, 
glabrous;  blades  as  in  the  radical  leaves. 

Inflorescence  an  exsert-pedunculate,  usually  open  panicle  9  to  20  inches  long; 
main  axis  glabrous  or  occasionally  scabrous,  pubescent  at  the  forks;  spikelets 
borne  singly  on  short,  scabrous  pedicels,  or  sometimes  sessile. 

Spikelets  l£  to  2  lines  long,  nearly  terete,  elliptical-lanceolate  to  oblong, 
bluntly  acute. 

Glumes  4,  glabrous,  membranaceous,  purple  or  pale  green;  2  lower  empty; 
first  broadly  ovate,  acute,  3-  to  7-nerved,  frequently  unsymmetrically,  one-third  to 
one-half  the  length  of  the  spikelet;  second  as  long  as  the  spikelet,  oblong,  bluntly 
acute,  5-  to  7-nerved. 

Flowers  2.  Lower  staminate;  glume  like  the  second  empty  glume;  palet  hyaline, 
thin-membranaceous,  2-nerved.  Upper  flower  hermaphrodite;  glume  coriaceous, 
minutely  corrugated,  obsoletely  few-nerved,  acute;  palet  2-nerved,  similar  in  text- 
ure to  the  glume;  stamens  3;  styles  long. 

PLATE  II;  a,  three  spikelets  enlarged;  b,  spikelet  opened  to  show  the  parts; 
c,  portion  of  the  base  of  the  culm,  and  the  corm  of  the  preceding  year.  On  the 
left,  in  6,  in  order  from  below,  are  the  lower  empty  glume,  first  flowering  glume,  and 
palet  of  the  staminate  flower,  on  the  right  the  second  empty  glume,  the  second 
flowering  glume,  and  to  the  left  of  the  stamens  and  pistil  the  palet  of  the  fertile 
flower. 

This  grass  should  be  one  of  great  agricultural  value.  Its  bulbous  rootstocks 
contain  a  store  of  moisture  which  enables  it  to  endure  a  protracted  drought,  and  as 
it  grows  of  large  size  it  would  produce  a  great  amount  of  fodder. 


PANICUM  BULBOSUM,  H.  B.  K. 


No.  3. 
PANICUM  CILIATISSIMUM  Buckley. 

Rootstock  and  roots  slender. 

Culms  varying  from  erect  at  the  ends  of  the  rootstock  to  procumbent  and  even 
creeping,  glabrous,  except  a  ring  of  reflexed  hairs  at  the  nodes;  erect  stems  from  a 
few  inches  to  2  feet  high,  commonly  with  short  sterile  branches,  slender,  the  inter- 
nodes  sometimes  3  inches  long;  creeping  stems  long,  thicker,  profusely  branching, 
with  shorter  internodes,  rooting  at  the  nodes. 

Leaves  with  long-ciliate,  usually  sparingly  hirsute  sheaths,  and  flat,  smooth,  or 
sometimes  slightly  hirsute  blades  tapering  from  base  to  apex.  Sheaths  of  the 
erect  stems  frequently  distant,  those  of  the  creeping  stems  shorter  but  mostly  con- 
tiguous. Blades  of  the  creeping  stems  seldom  exceeding  1|  inches,  those  of  the 
erect  plants  usually  longer. 

Inflorescence  a  small  narrow  panicle  2i  inches  long  or  reduced  to  a  few  spike- 
lets,  terminating  the  culm,  exsert-stipitate  in  the  erect  plant  (in  creeping  plants 
terminating  short  axillary  branches  as  well,  and  partly  sheathed,  all  intermediate 
stages  being  found),  bearing  the  spikelets  terminal  or  laterally  sessile  on  the  flat 
minutely  pubescent  branches  of  the  panicle. 

Spikelets  l£  to  2  lines  long,  oblong,  acuminate,  slightly  obcompressed. 

Glumes  4;  3  lower  membranaceous;  first  lanceolate,  acuminate,  glabrous,  3-  to 
5- nerved,  nearly  as  long  as  the  spikelet;  second  ovate,  short-acuminate,  pubescent, 
sometimes  minutely  villous-ciliate  near  the  margins,  many  (about  ll-)-nerved;  third 
similar  to  the  last,  but  glabrous  down  the  middle,  most  of  the  nerves  of  that  area 
obsolete;  fourth  (flowering)  glume  coriaceous,  indistinctly  few-nerved,  minutely 
corrugated,  bluntly  acute. 

Flowers  2.  Lower  reduced  to  a  hyaline,  2-nerved,  oblong  palet  subtended  by  the 
third  glume;  or  sometimes  with  3  stamens.  Upper  hermaphrodite;  palet  of  the 
same  texture  as  its  glume,  indistinctly  2-nerved;  glume  closely  embracing  the 
grain;  stamens  3. 

PLATE  III;  1,  erect  stem;  2,  creeping  stem;  a  spikelet  opened  to  show  the 
parts. 


PANICUM  CILIATISSIMUM,  Buckley 


No.  4. 
,    PANICUM  LACHNANTHUM  Torrey. 

Roots  slender. 

Culms  closely  tufted,  with  numerous  short  sterile  branches  from  near  the  base, 
erect  or  ascending,  1  to  2%  feet  high,  slender,  glabrous. 

Leaves  with  flat  blades  1  to  2  lines  wide;  sheaths  from  smooth  to  divaricately 
villous,  those  of  the  lower  part  of  the  stem  long  and  far  exceeding  the  short  inter- 
nodes,  those  (sheaths)  of  the  rootstock  densely  soft  villous;  ligule  about  !-£  lines 
long,  broadly  obtuse,  apical  margin  fimbriate;  blade  from  glabrous  to  minutely 
pubescent,  commonly  2  to  4  inches  long. 

Inflorescence  a  panicle  on  a  long  slender  peduncle.  Panicle  contracted,  4  to  9 
inches  long,  composed  of  7  to  9  erect  or  appressed  sessile  branches  1  inch  or  more 
long;  spikelets  closely  racemose  on  the  branches;  pedicel  flat;  branches  of  the  pani- 
cle triangular,  both  with  green  scabrous  angles. 

Spikelets  narrowly  to  broadly  lanceolate-acuminate,  1-J  to  2  lines  long,  showing 
an  inclination  toward  an  arrangement  in  2  rows  along  the  raceme. 

Glumes  4;  3  lower  membranaceous,  empty;  first  a  minute,  hyaline,  obtuse  scale 
from  £  line  long  to  nearly  obsolete;  second  narrowly  lanceolate,  acuminate,  3- to 
5-nerved,  densely  long- villous  on  the  back,  hairs  when  the  grain  is  mature,  spread- 
ing in  all  directions  as  if  from  a  point  in  the  center  of  the  spikelet;  third  similar 
to  the  last  but  broader  and  about  5-nerved,  its  middle  portion  glabrous,  intra- 
marginal  hairs  as  in  the  second  glume  and  similarly  spreading;  fourth  (flowering) 
glabrous,  thin,  coriaceous,  with  thin  membranaceous  margins,  indistinctly  3-nerved, 
minutely  roughened  in  longitudinal  lines,  lanceolate,  acuminate,  when  mature 
chestnut-brown. 

Flower  single,  hermaphrodite.  Palet  similar  in  texture,  shape,  and  color  to  the 
flowering  glume,  nerveless.  Stamens  3;  anthers  \  line  long,  one-half  as  broad. 
Stigmas  long,  cylindrical. 

Grain  inclosed  by  the  palet  and  its  glume,  oval,  obcompressed,  white,  slightly 
exceeding  f  line  long. 

PLATE  IV;  a,  spikelet  opened  to  show  its  parts,  on  the  left  the  second  glume 
and  flowering  glume,  on  the  right  the  third  glume  and  palet.  The  first  glume, 
which  should  stand  on  the  right,  is  omitted;  the  inflexed  membranaceous  margins 
of  the  flowering  glume  and  palet  are  not  shown;  and  the  ovary  is  represented  as 
of  the  size  of  a  mature  grain  with  the  anthers  twice  their  real  length. 

This  grass  grows  freely  on  stony  hills,  and  probably  is  capable  of  resisting 
drought.  It  seems  deserving  of  trial  as  an  agricultural  grass  for  the  southwest. 


PANICUM  LACHNANTHUM,  Torr. 


No.  5. 

SETARIA  GAUD  ATA  R.  &  S. 

Plant  annual. 

Rootstock  none.     Roots  slender. 

Culms  2  to  2£  feet  high,  branching  from  the  base,  scabrous  or  nearly  glabrous; 
nodes  provided  with  a  ring  of  silky  appressed  hairs;  "branches  usually  short  and 
sterile. 

Leaves  of  the  stem  4  or  5;  sheaths  usually  distant,  glabrous,  ciliate  on  the 
margins,  villous  at  the  apex;  blade  1  to  3  lines  broad,  usually  5  to  9  inches  long, 
flat,  glabrous  beneath,  scabrous  above;  ligule  about  1  line  long,  cut  nearly  to  the 
base  into  silky  hairs.  Radical  leaves  like  those  of  the  stem. 

Inflorescence  a  contracted  spike-like  panicle  3  to  4  lines  broad  (exclusive  of 
the  bristles),  3  to  6  inches  long,  on  a  moderately  long  exserted  peduncle;  branches 
of  the  panicle  shoit  (1  to  3  lines),  spikelets  sessile  or  nearly  so,  some  of  the 
pedicels  sterile  and  prolonged  into  slender  scabrous  bristles  6  lines  long  or  less. 
Spikelets  ovate,  acute,  semi-terete,  1  to  1|  lines  long. 

Glumes  4;  2  lower  empty,  membranaceous,  glabrous;  first  broadly  ovate,  acute, 
3-nerved,  one-half  the  length  of  spikelet;  second  broadly  oval,  obtuse  or  mucro- 
nate,  5-nerved,  nearly  as  long  as  the  spikelet,  fitting  closely  to  the  flowering  glume; 
third  like  the  second  but  slightly  longer,  acutej  and  subtending  a  rudimentary 
lanceolate  hyaline  palet;  fourth  (flowering),  when  in  position,  narrowly  ovate,  acute, 
coriaceous,  rounded  and  minutely  rugose-roughened  on  the  back,  obscurely  5-nerved. 

Flower  hermaphrodite.  Palet  lanceolate  when  in  position,  coriaceous  (the  in- 
folded margins  membranaceous),  flat  on  the  back  when  mature,  obscurely  2-nerved. 
Stamens  3.  Stigmas  2,  oblong. 

PLATE  V;  a,  spikelet  with  its  accompanying  bristle.  The  spikelet  is  opened 
to  show  its  parts.  The  flowering  glume  is  represented  too  short,  and  should  be 
acute,  while  the  back  of  the  palet  is  not  represented  as  flat. 

This  grass  has  much  the  habit  of  German  millet,  and  with  proper  cultivation 
would  probably  produce  an  abundant  crop. 


I 


SETARIA  CAUDATA,  B.  <t  S. 


CENCHRUS  MYOSUROIDES  H.  B.  K. 

Culms  erect  or  from  an  ascending  base,  usually  simple,  2  to  4  feet  high,  stout, 
glabrous,  glaucous. 

Leaves  of  the  stem  6  to  10;  sheaths  glabrous,  nearly  contiguous;  blade  glabrous 
to  minutely  strigose,  flat  or  sometimes  involute,  2  to  4  lines  wide,  commonly  5  to 
12  inches  long;  ligule  fimbriate  to  the  base.  Radical  leaves  early  dying. 

Inflorescence  a  short-pedunculate  or  partly  sheathed,  compact,  erect  spike  3  to 
4  lines  thick,  3  to  8  inches  long,  rachis  minutely  pubescent,  spikelets  borne  singly. 

Spikelets  2  to  2^  lines  long  surrounded  at  the  base  by  a  ring  of  many  retrosely 
barbed  stiff  bristles  of  different  lengths,  the  longest  equaling  the  spikelets;  body 
lanceolate,  acute,  terete. 

Glumes  4;  first  membranaceous,  ovate,  1-  to3-nerved,  acute,  one-half  the  length 
of  the  spikelet;  second  membranaceous,  ovate,  5-  to  7-nerved,  acute,  equaling  the 
spikelet;  third  like  the  second,  but  subtending  a  hyaline  2-nerved  palet  (this 
lanceolate  when  in  position);  fourth  (flowering)  like  the  second  and  third,  but 
rather  coriaceous,  the  nerves  more  obscure  and  seldom  green. 

Flower  hermaphrodite.  Palet  similar  in  shape  and  texture  to  its  glume,  but 
2-nerved.  Stamens  3,  anthers  linear,  about  1  line  long.  Stigmas  2,  linear. 

Grain  f  line  long,  somewhat  obcompressed,  quadrangular,  oblong,  very  obtuse, 
with  an  embryo  three-fourths  as  long,  when  mature  inclosed  in  the  glumes  and 
bristles,  the  whole  falling  off  together. 

PLATE  VI;  a,  spikelet  closed;  6,  spikelet  opened,  the  bristles  removed.  On  the 
right  in  b  are  the  first  glume,  third  glume  and  sterile  palet,  on  the  left  the  second 
glume,  flowering  glume,  and  its  palet. 

This  grass  will  grow  in  very  dry  soil,  and  will  produce  a  good  crop  of  forage, 
but  is  somewhat  objectionable  on  account  of  the  prickly  seed-envelopes. 


CENCHRUS  MYOSUROIDES,  H.  B.  K. 


No.  7. 
CENCHRUS  TRIBULOIDES  L. 

Plant  annual.     Roots  slender. 

Culms  glabrous,  a  few  inches  to  3  feet  high,  usually  branching  from  the  base 
and  procumbent,  rooting  at  the  lower  nodes,  or  sometimes  the  shorter  plants  erect. 

Leaves  of  the  stem  3  to  10;  sheaths  glabrous,  rarely  ciliate  on  the  margins 
above,  usually  loose,  commonly  contiguous;  blade  6  inches  long  or  less,  1  to  2  lines 
broad,  flat  or  sometimes  involute;  ligule  about  -^  line  long,  deeply  densely  fimbriate. 

Inflorescence  a  short-pedunculate  or  partly  sheathed  spike  of  clusters,  4  inches 
long  or  reduced  to  a  single  cluster,  the  rachis  nearly  smooth.  Clusters  composed 
of  2  to  3  spikelets  surrounded  by  an  involucre.  Involucre  thick,  coriaceous,  cleft 
to  the  base  on  the  side  next  the  rachis  or  on  both  sides,  inclosing  the  spikelets: 
the  outer  surface  provided  with  numerous  bristles  and  spines  flattened  below  and 
retrorsely  barbed,  those  toward  the  base  of  the  involucre  smaller,  the  larger  2$  lines 
long. 

Spikelets  2  to  3  in  each  involucre,  1  at  least  fully  developed  and  with  the 
following  structure  (the  others  rudimentary  in  various  degrees). 

Glumes  4;  3  lower  membranaceous;  first  short,  ovate,  acute,  1-  to  3-nerved, 
empty;  second  broadly  lanceolate,  5-nerved,  acute,  nearly  as  long  as  the  involucre, 
empty;  third  like  the  second,  but  subtending  a  flower;  fourth  (flowering)  a  little 
larger  and  similar  in  form  to  the  second  and 'third,  but  thin-coriaceous. 

Flowers  2.  Lower  staminate,  with  a  thin  hyaline  2-nerved  palet;  stamens  3. 
Upper  with  a  thin-coriaceous  palet,  hermaphrodite;  ovary  flattened,  circular  in 
outline;  stamens  3.  anthers  ^  line  long,  dehiscing  much  earlier  than  those  of  the 
staminate  flower. 

Grain  inclosed  in  the  spikelet,  spikelet  inclosed  in  the  involucre,  the  whole 
disarticulating  from  the  spike  together. 

PLATE  VII;  a,  external  view  of  the  involucre;  b,  the  same  cut  open  to  show 
the  spikelets;  c,  a  single  fully  developed  spikelet  opened  to  show  the  parts.  On 
the  left  are  the  second  glume,  the  fourth  glume,  and  the  hermaphrodite  flower;  on 
the  right  are  the  first  glume,  the  third  glume,  and  the  staminate  flower.  The  first 
glume  should  be  inserted  below  the  second,  and  is  represented  twice  too  long,  as 
are  the  anthers  of  the  hermaphrodite  flower. 

This  species  is  too  common  in  sandy  grounds,  where  its  spiny  burs  are  an  an- 
noyance to  men  and  beasts  and  an  injury  to  the  wool  of  sheep  that  graze  near  it. 


CENCHRUS  TRIBULOIDES,  Linn. 


No.   8. 

STENOTAPHRUM  AMERICANUM  Schrank. 

Rootstock  apparently  creeping.     Roots  fibrous-branched. 

Culms  creeping  and  rooting  at  the  nodes,  or  procumbent,  from  2  feet  long  to 
very  short,  simple  or  with  a  few  main  branches,  glabrous,  enlarged  at  the  nodes, 
and  there  provided  with  a  short  sterile  branch  or  fascicle  of  leaves. 

Leaves  of  the  stem  several,  pale  green;  sheaths  glabrous,  or  slightly  ciliate  on 
the  margin  above,  usually  loose  and  not  contiguous;  blade  2  to  3  lines  wide,  from 
8  inches  long  to  very  short,  flat,  thick  (nerves  obscure,  midrib  prominent  beneath), 
glabrous,  abruptly  rounded  at  the  apex,  rarely  acute;  ligule  minute,  densely  fim- 
briate. 

Inflorescence  a  usually  sheathed  spike  terminating  the  stem  and  main  branches; 
rachis  thickened  and  enlarged  (reaching  3  lines  in  diameter  and  4  inches  in  length) ; 
spikelets  embedded  singly  sessile,  or  with  1  to  3  additional  short-pedicellate  ones, 
at  each  joint,  arranged  along  2  nearly  opposite  sides  of  the  rachis  but  facing 
one  way. 

Spikelets  lanceolate-ovate,  1-J  to  2$  lines  long. 

Glumes  4;  first  mernbranaceous,  hyaline,  small,  nerveless,  and  obtuse  or  some- 
times one-half  the  length  of  the  spikelet;  second  membranaceous,  7-  to  11-nerved, 
ovate,  acute,  as  long  as  the  spikelet,  empty;  third  similar  in  form,  somewhat  cori- 
aceous, buto-nerved,  subtending  a  flower;  fourth  like  the  third,  but  more  coriaceous, 
also  subtending  a  flower. 

Flowers  2.  Lower  staminate;  stamens  3;  palet  coriaceous  below,  2-nerved. 
Upper  flower  hermaphrodite;  stamens  3;  stigmas  2,  cylindrical  or  club-shaped. 

PLATE  VIII;  figure  below  at  the  right,  joint  of  the  rachis  showing  2  spike- 
lets,  the  lower  sessile,  the  upper  pedicelled;  at  the  left,  spikelet  opened  to  show  the 
parts.  In  the  flower  on  the  right,  which  is  the  hermaphrodite  one,  the  stigmas 
should  be  twice  as  long  and  proportionally  broader.  The  stamens  have  matured 
earlier  and  are  not  shown. 

This  grass  grows  in  sandy  land  especially  near  the  sea-coast.  It  has  strong 
creeping  roots,  which  render  it  capable  of  enduring  great  drought.  It  has  been 
recommended  in  Florida  as  a  very  valuable  pasture  grass, 


STENOTAPHRUM  AMERICANUM,  Schkr. 


No.  9. 

THURBERIA  ARKANSANA  Bentham. 

Plant  annual. 

Rootstock  none.     Roots  very  slender. 

Culms  erect,  simple  or  branching  from  the  'base,  slender,  commonly  9  to  18 
inches  high,  sometimes  depauperate,  glabrous. 

Leaves  of  the  stem  3  to  5;  sheaths  contiguous,  glabrous  or  sparingly  villous, 
the  margin  villous-ciliate;  blade  flat,  1  to  4  inches  long,  1  to  2  lines  broad,  flaccid, 
scabrous,  and  usually  sparingly  minutely  villous-pubescent;  ligule  about  -£  line 
long,  the  apex  narrowly  fringed. 

Inflorescence  a  panicle  at  first  partly  sheathed,  finally  pedunculate,  3  to  6 
inches  long;  branches  slender,  seldom  exceeding  1  inch  in  length;  spikelets  borne 
singly  on  pedicels  1|  lines  long  or  shorter. 

Spikelets  linear,  1$  to  2  lines  long  (exclusive  of  the  awn),  nearly  terete,  jointed 
to  the  pedicel  below  the  glumes. 

Glumes  3;  first  and  second  of  equal  length,  similar,  lanceolate,  acute,  green, 
nerveless  or  obsoletely  3-nerved,  scabrous-pubescent  without,  apices  slightly  sep- 
arated; third  (flowering)  not  green  except  the  3  nerves,  glabrous,  rather  thick, 
lanceolate,  folded  and  compressed,  awned  on  the  back  a  little  below  the  apex;  apex 
cleft  half-way  to  the  origin  of  the  awn;  awn  slender,  i  to  ^  inch  long,  little  twisted, 
abruptly  bent  at  the  middle. 

Flower  single,  hermaphrodite;  rachilla  prolonged  above  the  flower  (!)  into 
a  minute  filiform  rudiment  about  ^  line  long,  naked  or  surmounted  by  a  minute 
scale;  palet  very  thin,  hyaline,  narrowly  linear,  2-nerved;  lodicules  2,  about  ^  line 
long;  stamens  3,  anther  oblong,  about  £  line  long;  stigmas  cylindrical,  on  short 
distant  styles. 

Grain  linear-oblong,  remaining  closed  within  the  glumes,  the  spikelet  disartic- 
ulating below  them. 

Plate  IX;  a,  first  (on  the  left)  and  second  glumes;  6,  flowering  glume  and 
flower.  The  rudimentary  prolongation  of  the  rachilla  shown  in  b  is  usually  twice 
as  long  and  is  inserted  at  a  point  on  the  axis  near  the  middle  of  the  base  of  the 
palet,  not  on  the  flowering  glume,  as  shown  in  the  figure. 


THURBERIA  ARKANSANA,  Benth. 


No.  10. 

HILARIA  CENCHROIDES  H.  B.  K.,  var.  TEXAN  A  Vasey. 

Plant  perennial. 

Rootstock  none.     Roots  slender,  branching. 

Stems  of  two  kinds,  (1)  runners  and  (2)  normal  culms.  Runners  with  1  or 
few  nodes,  producing  a  plant  at  each;  internodes  several  inches  long,  slender,  ter- 
ete, glabrous.  Culms  erect,  6  to  12  inches  high,  slender,  densely  tufted  from  a 
single  rootstock,  glabrous,  retrosely  long-villous  at  the  nodes. 

Leaves  of  the  stem  2  to  4;  sheaths  about  1  inch  long,  distant,  tightly  sheathing, 
glabrous;  blade  £  to  1  line  wide,  seldom  exceeding  3  inches  in  length,  flat,  scab- 
rous above  and  on  the  margins,  rarely  beneath,  otherwise  smooth  except  sometimes 
a  few  long  hairs.  Root-leaves  similar,  several  on  each  stem,  sheaths  imbricated. 

Inflorescence  a  usually  slender-pedunculate  spike  f  to  l£  inches  long;  rachis 
flat,  zigzag,  minutely  pubescent,  spikelets  inserted  in  clusters  of  3  (resembling  a 
single  spikelet)  on  opposite  sides,  contiguous  or  one-half  overlapping. 

Spikelets  2%  to  3£  lines  long,  the  parts  spreading  above. 

(1)  MIDDLE  SPIKELETS. 

Glumes  3;  first  and  second,  equal,  similar,  nearly  as  long  as  the  spikelet,  body 
many-nerved,  coriaceous  below,  scabrous,  compressed,  at  the  middle  separating 
into  two  linear  obtuse  spreading  lobes  becoming  membranaceous-hyaline  at  the 
apex,  bearing  in  the  fork  an  awn  slightly  exceeding  the  spikelet;  third  (flowering) 
broadly  oblong  below,  hyaline,  3-nerved,  compressed,  abruptly  tapering  from  below 
the  middle  into  a  slender  compressed  neck. 

Flower  pistillate.  Palet  similar  to  the  flowering  glume  but  narrower  and 
2-nerved,  and  with  it  forming  a  cavity  below  and  a  neck  above.  Ovary  and  after- 
ward the  grain  inclosed  in  this  cavity.  Styles  long,  lying  in  the  neck,  very  slender 
above;  stigmas  cylindrical,  the  body  thick. 

(2)  LATERAL  SPIKELETS. 

Glumes  4;  first  similar  to  that  of  the  middle  spikelet,  but  inequilateral,  and 
with  shorter  awn;  second  similar  to  the  first,  but  merely  mucronate;  third  and 
fourth  each  subtending  a  flower,  alike,  thin-membranaceous,  lanceolate,  hyaline, 
1-nerved  or  with  1  or  2  additional  lateral  nerves. 

Flowers  staminate.  Palet  thin-membranaceous,  hyaline,  2-nerved,  linear. 
Stamens  3,  anther  narrowly  linear. 

Grain  inclosed  primarily  in  its  palet  and  glume,  these  becoming  shining-coria- 
ceous, the  whole  inclosed  in  the  empty  glumes,  the  entire  cluster  of  spikelets 
dropping  off  together. 

PLATE  X;  a,  cluster  of  three  spikelets;  &,  staminate  flowers  of  one  of  the  lateral 
spikelets;  c,  pistillate  flower  of  the  middle  spikelet.  In  b,  one  of  the  spikelets 
should  be  sessile.  In  c,  the  stigmas  are  nearly  twice  too  short  and  proportionally 
too  narrow,  their  bodies  too  slender,  and  the  filaments  not  thick  enough  below. 

This  species  differs  from  the  Mexican  type  in  being  more  slender,  with  longer 
culms,  more  spikelets  in  the  spike,  and  the  spikelets  narrower  and  smooth  instead 
of  scabrous. 


HILARIA  CENCHROIDES,  H.  B.  K. 


No.  11. 

HILARIA  MUTICA  Bentham.     . 

Plants  perennial. 

Roots  thick,  simple,  with  a  cork-like  covering.  Rootstock  creeping,  woody, 
scaly-sheathed. 

Culms  erect  or  from  an  ascending  base,  9  to  20  inches  high,  somewhat  tufted, 
usually  with  many  sterile  branches  below,  glabrous,  sometimes  hairy  at  the  nodes. 

Leaves  of  the  stem  4  to  10;  sheaths  imbricated  below,  distant  above,  glabrous, 
the  margins  sometimes  ciliate  above;  blade  I  to  li  lines  broad,  reaching  6  inches 
long,  flat  or  involute,  usually  slightly  scabrous,  otherwise  smooth;  ligule  about  % 
line  long,  fimbriate. 

Inflorescence  a  close  spike,  pedunculate  or  scarcely  exserted,  1|  to  3  inches 
long;  spikelets  arranged  in  clusters  of  3  on  opposite  sides  of  the  flat  rachis,  imbri- 
cated. 

Spikelets  2  to  3  lines  long,  with  a  tuft  of  long  hairs  surrounding  the  cluster 
at  the  base. 

(1)  MIDDLE  SPIKELETS. 

Glumes  3;  first  and  second  alike,  oblanceolate,  1-nerved  at  the  base,  with  cili- 
ate membranaceous  margins,  the  nerve  splitting  above  into  several  branches,  con- 
tinued into  short  aristae,  or  the  lateral  ones  joined  into  a  fimbriate  membrane; 
third  (flowering)  glume  membranaceous,  linear,  obtuse,  3-nerved. 

Flower  hermaphrodite.  Stamens  3;  anther  narrow-linear,  \  to  2  lines  long,  the 
narrow  cells  free  at  the  ends.  Styles  2,  long;  stigmas  long,  narrow-cylindrical, 
with  thick  bodies,  exserted  from  the  apex  of  the  tube  formed  by  the  palet  and 
glume. 

(2)  LATERAL  SPIKELETS. 

Glumes  commonly  5  to  6;  two  lower  empty,  upper  successively  shorter,  apices 
of  all  even;  first  lanceolate,  several-nerved,  ciliate  on  the  membranaceous  margins 
and  apex,  usually  with  a  short  lateral  awn  on  the  margin  nearest  the  middle 
spikelet;  second  similar,  but  linear  and  unawned;  flowering  glumes  narrowly  quad- 
rangular-oblong, truncate,  membranaceous,  3-nerved. 

Flowers  staminate.  Palet  similar  to  the  glume  but  narrower,  2-nerved. 
Stamens  3,  similar  to  those,  of  the  middle  spikelet,  those  of  the  upper  flowers  suc- 
cessively shorter. 

Grain  inclosed  in  the  finally  coriaceous  and  shining  flowering  glume  and 
palet,  these  remaining  attached  in  the  cluster  of  spikelets,  the  whole  dropping  off 
together. 

PLATE  XI;  a,  two  lateral  spikelets  of  a  cluster,  and  b,  middle  spikelet  opened 
to  show  the  parts.  The  cluster  is  viewed  from  the  side  toward  the  rachis  of  the 
spike.  The  lateral  awn  of  the  two  glumes  uppermost  in  a  is  not  shown,  nor  are  the 
stamens  of  the  upper  flowers  of  the  lateral  spikelets  shown.  In  b,  the  styles  are 
those  of  an  unopened  flower,  and  in  all  cases  the  cells  of  the  anthers  are  repre- 
sented as  united  even  to  their  ends. 

This  species  and  another  similar  one  (H.  Jamesii]  are  called  gietta  by  tho 
Mexicans,  and  in  some  localities  also  called  'black  grama.'  In  southern  New 
Mexico  and  Arizona  they  are  the  prevailing  grama  grasses,  taking  the  place  of  the 
white  grama  (Bouteloua  oligostacliya}  which  covers  the  plains  of  western  Kansas 
and  Nebraska.  The  species  here,  described  is  one  of  the  most  important  forage 
grasses  of  this  region. 


HILARIA  MUTICA,  Benth. 


No.  12. 
^EGOPOGON  GEMINIFLORUS  H.'B.  K.* 

Plant  annual. 

Culms  procumbent  and  branching  at  the  base,  or  even  creeping  and  rooting  at 
the  lower  nodes ;  erect  parts  about  1  foot  high,  very  slender,  glabrous. 

Leaves  of  the  stem  3  to  6  ;  sheaths  slender,  glabrous,  usually  not  quite  con- 
tiguous ;  blade  |  to  1  line  broad,  i  inch  long,  flat,  flaccid,  glabrous  ;  ligule  con- 
spicuous, about  1  line  long,  the  apex  short-lacerate. 

Inflorescence  racemose ;  spikelets  in  umbels  of  3,  one  nearly  sessile ;  umbels 
on  short,  slender,  scabrous  peduncles,  usually  turned  to  one  side,  in  a  raceme  1-J 
to  3  inches  long ;  rachis  slender,  scabrous. 

Spikelets  lanceolate,  acute,  excluding  the  awns  about  2  lines  long,  pedicelled 
ones  a  little  smaller. 

Glumes  3  ;  first  and  second  similar,  1-nerved,  made  up  of  a  narrow  body  ex- 
current  into  an  awn,  and  2  narrow,  lateral,  membranaceous,  from  truncate  to 
acuminate  wings  (one  shorter  than  the  other) ;  third  (flowering)  lanceolate, 
3-nerved,  each  nerve  excurreut  into  an  awn,  middle  one  (shorter  in  the  pedicelled 
spikelets)  nearly  as  long  as  the  spikelet,  lateral  ones  minute. 

Flower  single,  hermaphrodite.  Palet  membranaceous,  lanceolate,  2-nerved, 
each  nerve  excurrent  into  a  minute  tooth.  Stamens  3,  anthers  about  f  line  long, 
linear,  the  cells  joined  only  at  the  middle.  Stigmas  short,  cylindrical. 

Grain  not  seen,  but  probably  inclosed  in  the  spikelets,  the  umbel  of  3  drop- 
ping off  together. 

PLATE  XII;  lower  figure,  cluster  of  three  spikelets;  upper  figure,  spikelet 
opened  to  show  the  parts.  The  lateral  lobes  of  the  first  and  second  glumes  are 
broader  and  usually  less  acute  than  in  the  figure.  In  the  upper  figure  the  position 
of  the  first  glumes  is  reversed,  and  in  both  figures  the  stamens  and  pistils  are 
omitted. 


*  This  description  was  made  from  a  single  set  of  specimens  cultivated  from  Mexican  seed.  They 
are  taken  to  be  the  typical  form  of  H.  B.  K.  Several  forms  whose  specific  relationships  have  not 
all  been  well  worked  out  occur  in  the  southwestern  United  States  and  Mexico,  and  none  of  them, 
although  they  may  prove  to  be  varieties  of  this  species,  were  noted  in  writing  the  description. 


^EGOPOGON  GEMINIFLORUS,  H.  B.  K. 


No    13. 

CATHESTECUM  ERECTUM  Vasey  &  Hackel. 

Plant  perennial. 

Roots  slender.     Rootstock  none. 

Stems  of  two  kinds,  (1)  runners  and  (2)  erect  culms.  Runners  slender,  with 
iiiternodes  few  to  several  inches  long,  glabrous,  arcuate,  giving  rise  to  a  new  plant 
at  each  node.  Culms  densely  tufted  below,  many  of  them  short  and  leafy,  a  few 
elongated,  very  slender,  6  to  10  inches  high,  glabrous. 

Leaves  of  the  root  numerous;  sheath  short,  £  to  1  inch  long,  glabrous,  long- 
ciliate  at  the  apex;  blade  3  inches  or  less  long,  about  i  line  wide,  scabrous  on  the 
margins,  otherwise  glabrous  or  rarely  with  a  few  long  hairs;  ligule  minute,  fim- 
briate.  Leaves  of  the  stems  2  or  3;  sheaths  about  1  inch  long,  distant,  otherwise 
like  those  of  the  root;  blade  from  1  inch  long  to  almost  wanting. 

Inflorescence  racemose;  spikelets  in  a  raceme  of  4  to  8  clusters;  racemes  slender- 
pedunculate,  about  1  inch  long,  single  or  2  or  3  together  from  the  uppermost  sheath ; 
rachis  very  slender,  flat,  glabrous  or  slightly  scabrous;  clusters  short-pedicellate, 
composed  of  3  spikelets,  middle  spikelet  short-pedicelled,  lateral  nearly  sessile. 

Glumes  4  to  6;  first  small,  truncate-cuneate,  empty,  nearly  nerveless;  second 
empty,  lanceolate,  1-iierved;  others  subtending  flowers,  4-lobed,  3-nerved,  more 
or  less  scabrous  on  the  back,  the  nerves  extending  into  a  short  scabrous  awn 
between  the  lobes. 

Flowers  3  to  4,  hermaphrodite  (?);  palet  lanceolate,  2-nerved,  stamens  3,  an- 
thers 1  to  1|  lines  long;  pistils  not  detected;  sterile  prolongation  of  the  rachilla 
sometimes  found  at  the  apex  of  the  spikelets. 

Grain  not  found. 

PLATE  XIII;  a,  cluster  of  spikelets;  b,  first  glume;  c,  second  glume;  d  and  e, 
two  flowering  glumes;  /,  palet,  from  the  back;  g  and  h,  palets,  from  the  front; 
i,  sterile  prolongation  of  the  rachilla;  j,  stamens  and  pistils;  k,  anther  and 
upper  portion  of  filament. 

This  grass  is  found  on  the  arid  bluffs  of  the  Rio  Grande  in  Texas,  and  westward 
near  the  Mexican  border  as  far  as  Sonora.  It  is  too  small  to  be  of  much  economic 
importance. 


\\    // 


CATHESTECHUM  EKECTUM,  Vasty  et  Hackel. 


No.  14. 

TRAGUS  RACEMOSUS  Hall. 

Plant  annual. 

Hoots  very  slender. 

Stem  branching  and  procumbent  at  the  base,  sometimes  rooting  at  the  lower 
nodes,  glabrous,  15  inches  or  less  in  height;  depauperate  plants  sometimes  simple, 
erect,  and  but  2  to  3  inches  high. 

Leaves  of  the  stem  3  to  6;  sheaths  usually  not  contiguous,  glabrous,  often  some- 
what swollen;  blade  1  to  2  lines  broad,  1  to  2  inches  long,  or  the  uppermost  nearly 
obsolete,  glabrous  except  the  coarsely  ciliate-toothed  margins,  thick,  pale  green; 
ligule  a  dense  row  of  short  hairs. 

Inflorescence  a  dense  cylindrical  spike  of  clusters  of  spikelets  2|  to  3£  lines 
thick,  1  to  4  inches  long,  frequently  sheathed  at  the  base,  never  long-peduncled; 
clusters  nearly  sessile,  arranged  singly  on  all  sides  of  the  terete  minutely  pubescent 
rachis. 

Spikelets  2  to  3  in  each  cluster,  closely  spiked  (backs  together)  on  a  short  ra- 
chis; uppermost  commonly  reduced  to  a  single  echinate  glume;  lowest  and  usu- 
ally the  middle  one  perfect;  rachis  sometimes  produced  as  a  rudiment  above  the 
base  of  the  upper  flower. 

Glumes  3;  first  ovate,  small,  thin,  hyaline,  nerveless;  second  thick,  ovate  to 
lanceolate,  acute,  the  back  ridged  with  several  (commonly  5  to  7)  nerves  converg- 
ing at  the  apex  and  beset  with  hooked  spines;  third  (flowering)  lanceolate,  acute, 
mucronate-awned,  slightly  coriaceous,  glabrous,  3-nerved. 

Flower  single,  hermaphrodite.  Palet  lanceolate,  membranaceous,  2-nerved. 
Stamens  3;  anthers  short,  oblong;  stigmas  cylindrical,  slender. 

Grain  light-brown,  oblanceolate-oblong,  slightly  obcompressed,apiculate,short- 
stipitate,  about  ^  line  long. 

PLATE  XIV;  a,  cluster  of  two  spikelets  opened  to  show  the  parts.  The  spike- 
let  on  the  right  shows  the  first  glume  (very  small),  the  second  glume  (echinate), 
the  flowering  glume  and  its  palet,  and  between  them  an  organ  probably  meant  to 
represent  an  anther.  The  spikelet  to  the  left  shows  the  same  parts  except  the 
first  glume  which  is  replaced  by  the  rudimentary  prolongation  of  the  rachis.  The 
second  spikelet  should  be  raised  on  a  slight  prolongation  of  the  rachis. 

This  is  a  widely  distributed  semi-tropical  grass,  not  of  economic  value. 


TRAGUS  BACEMOSUS,  Hall. 


No.  15. 
ELIONURUS  BARBICULMIS  Hackel. 

Hootstock  not  seen,  apparently  creeping.  Roots  rather  thick,  mostly  simple, 
unbranched,  with  a  thin  brown  bark. 

Culms  densely  tufted,  erect,  1  to  3  feet  high,  slender,  rigid,  below  the  nodes 
pilose,  a  little  lower  scabrous,  and  lower  yet  glabrous;  many  short,  producing  only 
leaves. 

Leaves  of  the  stem  3  to  5;  sheaths  slender,  usually  not  contiguous,  glabrous, 
sparingly  long-ciliate  on  the  margins  above;  blade  8  inches  long  or  less,  the  up- 
permost often  entirely  wanting,  about  £  line  wide,  closely  involute,  long-pilose 
on  the  margins  below,  densely  hairy  for  a  short  distance  from  the  liglue  within, 
otherwise  glabrous,  rising  erect  from  the  sheath;  ligiile  a  dense  row  of  stiff  hairs. 
Root  leaves  and  those  of  the  abortive  stems  similar  to  the  last,  but  reaching  1  foot 
in  length,  tips  frequently  flexuous. 

Inflorescence  a  more  or  less  pedunculate  terminal  distichous  spike,  2  to  4 
inches  long,  about  3  lines  thick,  densely  villous  on  both  the  rachis,  pedicels,  and 
spikelets;  rachis  flat. 

Spikelets  inserted  2  together  on  one  side  of  the  rachis  at  each  joint;  one  ses- 
sile, 3  to  4  lines  long;  other  pedicelled,  of  about  the  same  length,  including  the 
pedicel. 

Grlumes  4;  first  lanceolate,  several-nerved,  densely  villous  on  the  back,  apex  bifid 
into  two  slender  points;  second  lanceolate,  3-nerved,  more  or  less  villous  in  the 
middle  of  the  back,  these  two  inclosing  the  rest  of  the  spikelet;  third  thin,  meni- 
branaceous,  laterally  2-nerved,  ciliate  on  the  inflexed  margins;  fourth  (flowering) 
lanceolate,  membranaceous,  1-  to  3-nerved,  glabrous. 

Flower  of  sessile  spikelet  hermaphrodite;  palet  lanceolate,  minute,  membra- 
naceous; lodicules  2,  about  £  line  long,  thick;  stamens  3,  linear,  anthers  l£  to  2 
lines  long;  stigmas  long,  cylindrical.  Flower  of  pedicelled  spikelet  staminate; 
palet  wanting,  lodicules  as  in  the  hermaphrodite  flower;  stamens  3,  shorter  than 
the  others. 

Grain  light-brown,  obcompressed,  elliptical-lanceolate,  acute  at  each  end;  em- 
bryo occupying  half  its  length.  Rachis  of  the  spike  finally  disarticulating  just 
below  the  nodes,  bearing  the  2  spikelets,  one  containing  the  grain. 

PLATE  XV;  a,  portion  of  the  rachis  of  the  spike,  showing  the  two  spikelets  at 
a  node,  opened  to  show  their  parts.  The  palet  of  the  lower  spikelets  is  not  shown. 

This  species  occurs  on  rocky  hills  in  western  Texas,  southern  New  Mexico, 
and  Arizona,  and  the  adjacent  parts  of  Mexico. 


ELIONURUS  BARBICULMUM,  Hack. 


No.   16. 
HETEROPOGON    CONTORTUS  R.  &  S. 

Rootstock  short.     Roots  stout. 

Culms  tufted,  smooth,  branching  above,  erect,  about  3  feet  high. 

Leaves  6  to  12  inches  long,  upper  ones  gradually  shorter;  blade  flat,  upper  sur- 
face and  margins  rough,  lower  surface  smooth;  sheath  smooth,  much  flattened. 

Inflorescence  spicate,  cylindrical,  about  2  inches  long  without  the  awns,  main 
rachis  smooth. 

Spikelets  3  to  5  lines  long,  in  pairs,  lower  sessile  and  perfect,  upper  on  a  short 
pedicel,  and  staminate  only.  Male  spikelets  turned  to  one  side  of  the  spike,  almost 
concealing  the  fertile  ones. 

Glumes  in  the  female  s'pikelets  4,  outer  hard,  hairy,  convolute;  second  much 
narrower,  hard,  3-nerved;  third  very  thin,  hyaline,  smaller;  fourth  hyaline  at  the 
base,  above  extended  into  a  hard  twisted  and  bent  awn  2  to  3  inches  long  or 
more.  Glumes  of  the  male  spikelet  4;  first  ovate-lanceolate,  flattish,  keeled  near 
the  margin,  thick,  green,  ciliate,  many-nerved,  margins  thin;  second  thinner,  nar- 
rower, 3-nerved,  ciliate  on  the  margin;  third  and  fourth  hyaline,  somewhat 
shorter. 

Stamens  3.     Styles  2. 

PLATE  XVI;  a,  pair  of  spikelets,  the  upper  male,  the  lower  female,  with  the  long 
twisted  and  pubescent  awn;  b,  a  male  flower  spread  open  to  show  the  parts.  The 
fourth  glume  is  omitted. 

This  grass  furnishes  a  large  amount  of  foliage,  and  is  deserving  of  trial  in  cul- 
tivation. 


HETEROPOGON  CONTORTUS,  B.  <t  S. 


No.  17. 
TRACHYPOGON  POLYMORPHUS  Hack. 

Rootstock  short.     Roots  strong. 

Culms  tufted,  smooth,  bearded  at  the  joints,  unbranched,  erect,  2  to  3  feet  high. 

Leaves.  Lower  ones  6  to  12  inches  long,  about  2  lines  wide,  attenuated  to  a 
point,  scabrous,  sparingly  hairy  toward  the  base:  sheaths  hairy,  the  lower  ones 
longer  than  the  internodes,  the  upper  shorter;  ligule  1  to  2  lines  long,  ovate-lance- 
olate, sparingly  hairy. 

Inflorescence  a  narrow,  slender  spike,  rather  loose,  4  to  6  inches  long,  erect; 
the  rachis  slightly  hairy  at  the  joints,  otherwise  smooth. 

Spikelets  in  pairs.  3  to  4  lines  long,  each  1-flowered,  the  lower  flower  sessile 
and  male  only,  the  other  on  a  short  pedicel  and  perfect.  Male  spikelets:  first  and 
second  glumes  thick;  first  oblong-linear,  7-  to  9-nerved,  sparsely  pubescent,  ob- 
tuse, ciliate  at  apex;  second  lanceolate-oblong,  3-nerved,  acute;  third  and  fourth 
thin,  hyaline.  Female  spikelet  like  the  male  except  the  flowering  glume;  this 
terminating  in  a  hairy,  twisted  awn,  about  2  inches  long.  Stamens  3.  Styles  2, 
stigmas  plumose. 

PLATE  XVII;  a,  pair  of  spikelets  opened  to  show  the  parts. 


TRACHYPOGON  POLYMORPHUS,  Back. 


No.  18. 
ANDROPOGON     CIRRHATUS  Hackel. 

Rootstock  short.     Roots  strong. 

Culms  tufted,  2  to  3  feet  high,  slender,  branching  above,  of  6  to  8  joints  ;  lat- 
eral branches  arising  singly,  slender,  becoming  long-exserted. 

Leaves.  Sheaths  narrow,  close,  smooth,  striate  ;  ligule  short,  truncate,  smooth; 
blade  3  to  §  inches  long,  1  to  2  lines  wide,  attenuated  to  a  long  acute  point,  rigid, 
smooth,  except  the  roughish  margins. 

Inflorescence  terminal  on  the  culm  and  its  branches,  in  a  spike-like  raceme 
about  2  inches  long  consisting  of  10  to  15  joints;  rachis  smooth. 

Spikelets  in  pairs.  Female  spikelets  sessile,  about  3  lines  long ;  first  glume 
linear-lanceolate,  thick,  2-toothed  at  apex,  smooth  except  the  scabrous  keel  and 
margins,  7-  to  9-nerved;  second  glume  slightly  shorter  than  the  first,  acute,  much 
thinner,  3-iierved  above,  smooth;  third  glume  one-fourth  shorter  than  the  first, 
hyaline,  linear-oblong,  obtuse.  2-uerved,  ciliate  on  the  margins;  fourth  glume  as 
long  as  the  third,  hyaline,  bifid,  attached  below  to  an  awn  6  to  8  lines  long.  Male 
spikelet  rather  shorter  than  the  female,  about  equaling  its  pedicel;  pedicel  smooth 
except  a  tuft  of  cilia  near  the  apex;  glumes  4,  much  as  in  the  female,  but  without 
the  awn  of  the  third  glume. 

PLATE  XVIII;  a,  pair  of  spikelets;  5,  female  spikelet  opened  to  show  the 
parts;  c,  male  spikelet  opened. 

This  is  related  to  the  broomsedge  (A.  scoparius),  and  is  rather  rare. 


ANDROPOGON  CIRRHATUS,  Hack. 


No.  19. 
ANDROPOGON    HIRTIFLORUS  Kunth. 

Culms  2  to  4  feet  high,  densely  tufted  on  a  short  rootstock,  erect,  rather  slen- 
der and  wiry,  with  generally  single  branches  from  the  upper  joints;  lower  inter- 
nodes  compressed,  furrowed  on  the  inner  face ;  branches  becoming  long-exserted 
and  flower-bearing  at  the  extremity,  smooth. 

Leaves  crowded  below,  distant  above ;  lower  sheaths  compressed,  short,  with 
scattering  hairs  or  nearly  smooth ;  ligule  membranaceous,  short,  truncate ;  blade 
flat,  2  to  6  inches  long,  1  to  2  lines  wide,  firm  and  erect,  rather  scabrous,  acumi- 
nate. 

Inflorescence  terminating  the  culm  and  branches  as  a  loose,  narrow,  few-flow- 
ered, spike-like  raceme,  consisting  of  10  to  20  joints,  2  to  3  inches  long ;  branches 
slender,  long-exserted  from  the  sheaths. 

Spikelets  in  pairs  at  the  joints  of  the  flattened  hairy  rachis,  lower  perfect  and 
fertile,  upper  sterile.  Perfect  spikelet  4  lines  long ;  glumes  4,  two  of  hard  texture 
and  two  hyaline ;  first  linear-lanceolate,  roughened  on  the  back,  covered  with  long 
white  hairs ;  second  thinner,  keeled,  without  hairs,  minutely  scabrous ;  third 
hyaline,  a  little  shorter  than  the  second,  slightly  ciliate,  deeply  bifid,  attached  be- 
low to  its  twisted  and  bent  awn,  which  is  8  or  10  lines  long  ;  fourth  hyaline,  entire, 
inclosing  the  proper  flower.  Sterile  spikelet:  pedicel  about  2  lines  long,  flattened, 
cilate  ;  glumes  generally  2;  first  lanceolate,  acuminate,  green,  thick,  hirsute;  second 
hyaline,  inclosed  by  the  first. 

PLATE  XIX;  a,,  pair  of  spikelets,  the  perfect  one  sessile,  and  the  sterile  one  on 
a  pedicel ;  b,  perfect  flower  with  the  glumes  spread  out.  The  outer  or  first  glume 
does  not  show  the  long  hairs. 

This  species  also  is  related  to  A.  scoparius.  It  is  found  on  rocky  hills  in 
western  Texas,  in  the  Santa  Catalina  and  Huachuca  Mountains  of  Arizona,  and  in 
Mexico. 


No.  20. 

ANDROPOGON  SACCHAROIDES  Swartz. 

Rootstock  short.     Roots  strong. 

Culms  tufted,  smooth  (nodes  bearded  or  in  some  forms  smooth),  simple  or 
branched,  erect,  2  to  4  feet  high,  often  with  5  or  6  joints. 

Lower  leaves  1  foot  or  more  long;  blade  flat,  narrow,  acuminate,  somewhat  scab- 
rous on  both  surfaces  and  on  the  margins;  sheaths  smooth,  striate,  shorter  than 
the  internodes,  open;  ligules  broadly  ovate,  laciniate. 

Inflorescence  paniculate,  oblong,  about  4  inches  long,  composed  of  numerous 
(20  to  50)  closely  approximate  and  appressed  sessile  spike-like  branches  1  inch  or 
more  long  ;  spikelets  imbricated. 

Spikelets  in  pairs  at  the  joints  of  the  branches,  one  sessile  and  perfect,  the  other 
on  a  short  pedicel  and  either  male  or  imperfect.  Perfect  spikelets  2  lines  long  with 
2  outer  hard  glumes  and  2  inner  hyaline  ones;  first  about  7-nerved,  sparsely 
hairy,  2-toothed  at  the  apex,  second  obscurely  3-nerved,  third  and  fourth  hyaline, 
latter  terminating  in  a  twisted  awn  sometimes  8  or  10  lines  long.  Male  or  sterile 
spikelet  on  a  pedicel  of  about  its  own  length,  consisting  of  only  1  linear,  pubescent, 
5-  to  7-nerved,  glume;  pedicel  covered  with  long,  fine,  white  hairs.  , 

PLATE  XX;  a,  perfect  spikelet;  6,  both  the  sterile  and  perfect  spikelets. 

This  species  is  common  on  rocky  banks  and  borders  of  streams.  It  extends 
northward  to  southern  Colorado  and  Kansas,  and  deserves  trial  as  an  agricultural 
grass  for  dry  and  sandy  lands.  There  are  several  varieties. 


ANDROPOGON  SACCHAROIDES,  Swz. 


No.  21. 

ANDROPOGON    WRIGHTII  Hackel. 

Rootstock  thick.     Roots  very  strong. 

Culms  csespitose,  2  to  3  feet  high,  unbranched,  smooth,  slightly  hairy  at  the 
nodes. 

Leaves.  Sheaths  smooth,  striate,  shorter  than  the  internodes ;  ligules  1  line 
long,  obtuse,  smooth;  blade's  5  to  12  inches  long,  2  to  3  lines  wide,  light  green, 
smooth,  the  margins  scabrous. 

Panicle  2  to  3  inches  long,  consisting  of  5  to  7  clustered  or  approximate  spike- 
like  branches  1£  to  2  inches  long,  shortly  pedicellate,  erect,  and  densely  flowered; 
rachis  flattened,  hairy,  ciliate. 

Spikelets  about  3  lines  long,  in  pairs,  one  female,  one  male.  Female  spikelet 
sessile,  lance-oblong,  hairy  at  the  base,  sparsely  hairy  on  the  back  below ;  first 
glume  thick,  7-nerved  above ;  second  nearly  equal  to  the  first,  3-nerved  ;  third  and 
fourth  hyaline,  fourth  with  an  awn  £  inch  long.  Male  spikelet  on  a  ciliate  pedicel 
of  half  its  length,  about  3  lines  long;  first  glume  9-  to  11-nerved  at  the  base,  ciliate 
on  the  margins  above;  second  more  acute,  3-nerved,  ciliate;  third  hyaline,  nearly 
equaling  the  second ;  fourth  very  minute  or  wanting. 

PLATE  XXI ;  a,  pair  of  spikelets ;  b,  female  spikelet  spread  open  to  show  the 
parts ;  c,  male  spikelet  opened. 

This  resembles  the  preceding  species,  but  is  smaller  and  with  fewer  spikes.  It 
is  rare,  at  least  north  of  the  boundary. 


ANDROPOGON  WRIGHTII,  Hack. 


No.  22. 

ARISTIDA  ARIZONICA  Vasey. 

Rootstocks  unknown.     Roots  rather  stout,  simple  above,  with  a  thin  bark. 

Culms  erect,  simple,  closely  tufted,  1  to  2|  feet  high,  glabrous. 

Leaves  all  radical  or  originating  near  the  base  of  the  culm;  sheaths  imbricated, 
glabrous,  sometimes  6  inches  long ;  blades  commonly  3  to  5,  sometimes  10  inches 
long,  glabrous,  involute  when  dry  ;  ligules  a  minute  dense  ring  of  hairs. 

Inflorescence  an  exsert-pedunculate  panicle  4  to  12  inches  long;  branches  short, 
rarely  exceeding  2  inches,  nearly  erect;  spikelets  singly  sessile  or  short  pedunculate. 

Spikelets  (excluding  the  awns)  i  to  f  inch  long,  awl-shaped,  nearly  terete. 

Glumes  3  ;  first  linear,  two-thirds  the  length  of  the  spikelet,  membranaceous, 
1-nerved,  aristate,  acute  with  2  minute  accessory  teeth,  the  midnerve  and  awn- 
point  scabrous  ;  second  as  long  as  the  spikelet,  narrower  than  the  first,  similar  to  it. 
the  awn-point  a  little  longer ;  third  (flowering)  glume  coriaceous,  as  long  as  the 
second,  closely  involute,  very  slender,  scabrous ;  apex  twisted  two  or  three  times, 
then  produced  into  3,  straight,  terete,  not  twisted,  scabrous  awns  diverging  when 
dry,  usually  a  little  longer  than  the  spikelet ;  middle  one  slightly  the  longest ; 
rachilla  slightly  elongated  between  the  second  and  third  glumes,  densely  villous. 

Flower  single,  hermaphrodite.  Palet  minute,  nearly  1  line  long.  Lodicules  2, 
lanceolate,  as  long  as  the  palet.  Stamens  3,  anthers  linear  nearly  1  line  long. 
Stigmas  2,  cylindrical. 

Grain  awl-shaped,  about  4  lines  long,  closely  enwrapped  in  the  flowering  glume; 
rachilla  disarticulating  obliquely  just  atiove  the  second  glume. 

PLATE  XXII ;  a,  spikelet,  empty  glumes  spread  open ;  b,  the  same  empty 
glumes  removed,  flowering  glume  open  to  show  the  palet  and  stamens.  The 
stigmas  are  not  shown. 

A  common  grass  of  the  mesas  and  hills,  which  early  in  the  season  furnishes 
good  grazing  for  animals. 


ARISTIDA  ABIZONICA,  Vasey. 


No.  23. 

ARISTIDA  DIVARICATA  H.  B.  K. 

Rootstocks  not  seen.     Roots  rather  stout,  branching  only  below. 

Culms  tufted,  erect,  branching  only  at  the  base,  1  to  3  feet  high,  minutely  re- 
trosely  scabrous,  simple,  most  of  its  length  taken  up  by  the  panicle. 

Leaves  few,  those  of  the  stem  3  to  5;  sheaths  glabrous  or  minutely  scabrous, 
imbricated,  usually  with  a  few  long  hairs  at  the  apex;  ligule  a  row  of  short  hairs, 
with  sometimes  a  few  long  ones  intermixed;  blades  commonly  3  to  6  inches  long, 
involute,  usually  glabrous  beneath  and  scabrous  above,  never  hairy.  Root  leaves 
similar,  blades  a  little  shorter. 

Inflorescence  paniculate.  Panicle  usually  9  to  18  inches  long,  frequently  sheathed 
at  the  base;  rachis  nearly  terete,  glabrous;  branches  long  (the  lowest  commonly  5 
inches),  widely  spreading,  naked  at  the  base,  flat,  scabrous  on  the  margins;  spike- 
lets  borne  singly,  mostly  short-peduncled,  and  appressed  to  the  branches. 

Spikelets  linear-subulate  about  6  lines  long  (excluding  the  awns),  somewhat 
compressed. 

Glumes  3;  first  and  second  nearly  equal,  slightly  spreading,  narrowly  linear, 
acute,  membranaceous,  tawny  and  purple  in  color,  compressed,  1-nerved,  nerve 
scabrous  on  the  back;  third  (flowering)  coriaceous,  closely  involute  into  a  slender- 
cylindrical  tube,  scabrous  above,  slightly  shorter  than  the  empty  glumes,  scarcely 
twisted  at  the  apex,  produced  into  3  straight,  terete,  scabrous,  awns  slightly 
diverging  when  dry,  two  lateral  ones  about  as  long  as  the  body  of  the  glume,  mid- 
dle one  from  one-half  to  twice  longer.  Rachilla  elongated,  between  second  and 
third  glumes,  to  the  length  of  ^  line,  densely  short- villous. 

Flower  single,  hermaphrodite.  Palet  minute,  lanceolate,  %  line  long.  Lodi- 
cules  2,  shorter  than  the  palet,  linear-oblong.  Stamens  3;  anthers  linear,  £  line 
long.  Stigmas  2,  cylindrical. 

Grain  about  4  lines  long,  awl-shaped,  tightly  clasped  by  the  flowering  glume. 
Rachilla  disarticulating  above  the  second  glume. 

PLATE  XXIII;  a,  spikelet,  glumes  spread  apart  and  rhachilla  separated  at  its 
point  of  disarticulation.  The  hairs  on  the  apex  of  the  sheaths  are  not  shown,  nor 
those  on  the  rachilla  above  the  second  glume.  The  diameter  of  the  tube  of  the 
flowering  glume  is  often  nearly  twice  as  great. 

Grows  on  dry  or  sandy  hills  and  plains,  extending  to  southern  California. 


ARISTIDA  DIVARICATA,  H.  B.  K. 


No.  24 

STIPA  FLEXUOSA  Vasey. 

Culms  closely  set  on  a  short  horizontal  rootstock  with  slender  roots,  erect,  l£  to 
3  feet  high,  slender,  terete,  smooth,  unbranched. 

Leaves  of  the  stem  2  to  4 ;  sheaths  smooth,  close,  usually  imbricated ;  bl  ades  abo  ut 
1  line  broad,  a  few  inches  to  1  foot  long,  involute  or  the  upper  flat,  glabrous  on 
the  back,  minutely  pubescent  on  the  upper  surface,  hairy  at  the  angle  of  the 
ligule;  ligules  membranaceous,  1  to  2  lines  long,  lacerate  when  old,  broader  than 
the  blade. 

Inflorescence  paniculate.  Panicle  6  to  12  inches  long,  erect;  rachis  slender,  ter- 
ete, glabrous;  branches  slender,  flexuous,  few-angled,  scabrous,  bearing  towards 
the  apex  a  few  pedicelled  spikelets. 

Spikelets  single,  1-flowered,  011  pedicels  about  2  lines  long,  lanceolate,  awl-shaped 
when  closed,  6  to  9  lines  long  exclusive  of  the  awn. 

Glumes  3;  first  narrowly  lanceolate,  acute,  membranaceous;  glabrous,  1-nerved 
or  with  2  lateral  nerves  at  the  base,  hyaline  above,  green  or  purple  below,  as 
long  as  the  spikelet;  second  similar,  about  one-fifth  shorter,  3-  to  5-nerved;  third 
(flowering)  about  2|  lines  long  closely  involute  about  the  flower  into  an  awl-shaped 
terete  body,  villous  on  the  outside,  coriaceous  at  maturity,  5-nerved  apex  produced 
into  a  slender  scabrous  awn  twisted  in  a  right-handed  spiral  for  about  5  lines,  then 
bent,  then  twisted  as  before  for  about  3£  lines,  then  bent,  and  above  the  second 
bend  not  twisted.  Rachilla  elongated  between  the  second  and  third  glumes  to  the 
length  of  |  line,  villous. 

Flower  hermaphrodite.  Palet  about  one-third  the  length  of  the  glume,  oblong, 
obtuse,  hyaline.  Stamens  3;  anthers  linear,  1  to  1£  lines  long,  apex  of  each  cell  of 
the  anther  bearing  a  small  tuft  of  hairs.  Stigmas  rather  short,  oblong. 

Grain  awl-shaped,  about  2  lines  long,  inclosed  in  the  glume,  rachilla  disarticu- 
lating just  above  the  second  glume,  detached  portion  ending  in  a  sharp  point. 

PLATE  XXIV;  a,  and  b,  spikelet,  the  parts  spread  open  and  the  upper  portions 
of  the  rachilla  detached  at  the  point  of  disarticulation.  The  figure  does  not  show 
the  regular  bends  in  the  awn,  nor  the  tufts  of  hairs  at  the  apex  of  the  anther  cells. 

This  is  more  slender  than  8.  avenacea,  with  smaller  flowers,  the  flowering  glume 
pubescent  throughout,  and  the  apex  crowned  with  a  row  of  white  hairs. 


\ 


STIPA  FLEXUOSA,   Vasey. 


No.  25. 

MUHLENBERGIA  DISTICHOPHYLLA  Kuntli. 

Rootstock  not  seen.     Roots  strong,  branching  rather  early. 

Culms  tufted,  erect,  2£  to  4  feet  high,  simple,  glabrous,  glaucous  where  not 
sheathed,  stout,  rigid. 

Leaves  of  the  stem  2  to  4;  sheaths  long,  usually  imbricated,  not  hairy,  commonly 
minutely  roughened;  blade  3  to  12  inches  long,  a^out  1  line  wide,  flat  and  keeled 
or  conduplicate,  harsh,  scabrous  on  the  midrib  and  margins,  glaucous  green;  ligule 
membranaceous,  narrow,  long-acuminate,  sometimes  f  inch  long,  fragile.  Root 
leaves  with  sheaths  mostly  loose  and  compressed;  sheaths  sometimes  9  inches  long, 
and  the  entire  leaf  exceeding  3  feet. 

Inflorescence  paniculate.  Panicle  8  to  18  inches  long,  erect,  contracted; 
branches  numerous,  seldom  exceeding  3  inches,  scabrous  as  well  as  the  rachis. 

Spikelets  polygamous,  very  numerous,  borne  singly  on  slender  scabrous  pedicels, 
about  1  line  long,  linear-oblong,  obtuse  or  acute. 

Glumes  3;  first  and  second  nearly  equal,  membranaceous,  tawny,  often  purple  at 
the  base,  about  1  line  long,  slightly  scabrous  on  the  back,  acute,  or  sometimes  obtuse 
and  erose  at  the  apex,  1 -nerved,  rarely  with  2  rudimentary  lateral  nerves;  third 
(flowering)  similar  to  the  others,  densely  pilose  below,  with  a  strong  middle  nerve 
and  usually  2  indistinct  ones  on  either  side;  middle  nerve  in  the  hermaphrodite 
spikelets  produced,  from  below  the  apex  of  the  glume,  into  a  slender,  scabrous, 
terete,  somewhat  flexuous,  purple  awn  4  to  6  lines  long;  glume  of  the  staminate 
spikelets  awnless. 

Flowers  single  in  the  spikelets.  Palet  of  staminate  flower  thin,  membranaceous, 
lanceolate,  with  2  very  slender  approximate  nerves,  slightly  hairy  on  the  back; 
stamens  3,  anthers  linear,  nearly  as  long  as  the  spikelets.  Palet  of  hermaphrodite 
flower  similar  to  the  other;  stamens  3,  anthers  linear,  nearly  as  long  as  the  spike- 
let;  ovary  globular,  styles  long,  stamens  cylindrical. 

Grain  linear-oblong,  brown,  inclosed  in  the  glume  and  palet;  rachilla  disarticu- 
lating above  the  second  glume. 

PLATE  XXV;  1,  male  plant;  2,  hemaphrodite  plant;  a,  staminate  spikelet;  6, 
first  and  second  glumes  of  the  same;  c,  third  (flowering)  glume,  palet,  and  stamens 
of  the  same;/,  hermaphrodite  flower;  d,  first  and  second  glumes, of  the  same;  ey 
third  (flowering)  glume,  palet,  and  stigmas  of  the  same.  In  the  hermaphrodite 
flower  the  stamens  are  not  shown. 

A  coarse,  strongly  rooted,  perennial  grass,  perhaps  having  agricultural  value. 
It  is  one  of  the  grasses  called  saccato. 


MUHLENBERGIA  DISTICHOPHYLLA,  Munro. 


No.  26. 
MUHLENBERGIA  GRACILIS  Trinius. 

Rootstocks  short,  ascending. 

Culms  tufted,  erect,  9  to  24  inches  high,  uiibranched  above  the  base,  glabrous. 

Leaves  all  radical;  sheaths  of  the  outer  ones  short  (1  to  3  inches  long),  loose, 
flattened,  slightly  scabrous  on  the  back,  inner  longer  and  sheathing,  uppermost 
usually  reaching  to,  and  sheathing,  the  inflorescence;  blade  6  inches  or  less  long,  in 
line  with  the  sheaths,  usually  involute,  scabrous  on  the  back,  glabrous  above; 
ligule  niembranaceous,  about  i  to  i  inch  long,  at  the  base  broader  than  the  blade, 
apex  slender-acute  and  often  lacerate,  the  whole  shriveled  when  old. 

Inflorescence  paniculate.  Panicle  sheathed  or  long-pedunculate,  2  to  7  inches 
long,  erect  or  nearly  so;  rachis  scabrous;  branches  scabrous,  2  inches  long  or  less, 
nearly  erect. 

Spikelets  lanceolate,  acute,  2  lines  long  exclusive  of  the  awn,  borne  singly  on 
short  pedicels. 

Glumes  3;  first  lanceolate,  acuminate-aristate,  1-nerved,  scabrous  on  the  back, 
about  1  line  long,  lead-colored  below,  hyaline  above ;  second  slightly  longer,  sim- 
ilar in  texture,  scabrous  on  the  back,  ovate-oblong,  truncate,  3-nerved,  nerves  pro- 
duced into  aristate  points;  third  (flowering)  lanceolate,  involute,  1-nerved  or  with 
two  additional  nearly  marginal  nerves,  scabrous  on  the  back,  ciliate  on  the  mar- 
gins, as  long  as  the  spikelets,  straw-colored,  with  a  lead-colored  apex  tapering  into 
a  not  twisted  slender,  scabrous,  flexuous  awn  about  \  inch  long. 

Flower  single,  hermaphrodite.  Palet  lanceolate,  slightly  shorter  than  its 
glume,  obtuse  when  flattened,  2-nerved,  scabrous  on  the  back.  Stamens  3 ;  an- 
thers linear,  about  1  line  long.  Stigmas  cylindrical,  purple. 

Grain  not  seen.     Palet  and  glume  coriaceous  when  old. 

PLATE  XXVI ;  a  and  6,  spikelet,  the  parts  spread  open,  and  the  rachilla 
broken  above  the  second  glume;  c,  second  glume;  d,  first  glume;  e,  same  as  6, 
showing  the  back  of  the  flowering  glume. 

This  species  is  common  on  stony  ridges  or  hills  from  Mexico  to  Montana,  and 
a  small  form  occurs  in-  California. 


MUHLENBERGIA  GRACILJ8,  Trin. 


No.  27. 
EPICAMPES  MACROURA  Bentham. 

Rootstock  ascending,  thick.     Roots  strong,  little  branched. 

Culms  tufted,  erect,  2^  to  3£  feet  high,  glabrous,  simple. 

Leaves  of  the  r.oot  several;  sheaths  mostly  loose  above  and  involute,  6  to  9  inches 
long,  glabrous ;  blade  inserted  on  the  back  of  the  sheath,  erect,  commonly  1  foot 
long,  glabrous,  usually  involute ;  ligule  3  to  6  lines  long,  lanceolate,  coriaceous 
below,  membranaceous  above  and  on  the  margins,  broader  than  the  blade,  appear- 
ing as  a  direct  continuation  of  the  sheath.  Leaves  of  the  stem  2  to  3,  similar  to 
those  of  the  root ;  sheaths  imbricated  and  mostly  clasping  ;  blade  frequently  much 
shorter. 

Inflorescence  paniculate.  Panicle  short-pedunculate,  erect,  usually  8  to  16  inches 
long ;  rachis  terete,  scabrous,  branches  imbricated,  1  to  4  inches  long,  nearly  erect, 
scabrous,  bearing  the  spikelets  singly  on  short  scabrous  pedicels. 

Spikelets  nearly  terete,  lanceolate  and  acute  when  closed,  about  1  line  long. 

Glumes  3;  first  and  second  nearly  equal,  two-thirds  the  length  of  the  spikelet, 
oblong-lanceolate,  acute  or  acuminate,  1-nerved,  scabrous  on  the  back ;  third 
(flowering)  similar  in  texture,  a  little  longer,  oblong,  obtuse  and  bifid  at  the  apex, 
with  a  short  scabrous  awn  or  mucro  from  the  angle,  3-  to  5-nerved,  scabrous  on  the 
back. 

Flowers  single,  hermaphrodite.  Palet  equaling  the  third  glume,  oblong,  ob- 
tuse, 2-nerved,  rarely  scabrous.  Stamens  3:  anther  linear,  f  to  1  line  long.  Styles 
distinct,  short ;  stigmas  about  half  the  length  of  the  anthers,  oblong,  the  fimbrise 
long. 

Grain  dark  brown,  linear-oblong,  obtuse  or  acutish  at  base  and  apex,  terete,  in- 
closed in  the  flowering  glume  and  palet ;  rachilla  disarticulating  above  the  second 
glume. 

PLATE  XXVII ;  a,  first  (on  the  right)  and  second  glume ;  6,  flowering  glume  (on 
the  right)  and  palet,  open  to  show  the  stamens  and  pistil.  The  styles  are  much  too 
long,  while  the  stigmas  should  be  twice  as  long  and  nearly  four  times  broader. 

This  is  another  of  the  grasses  called  saccato,  or  saccatone. 

f 


EPICAMPES  MACROURA,  Benth. 


No.  28. 
EPICAMPES  RIGENS  Bentham. 

Rootsfocks  rather  slender,  ascending.     Roots  rather  stout,  little  branched. 

Stems  tufted,  erect,  commonly  2  to  6  feet  high,  glabrous,  simple.  Leaves  of  the 
root  few;  sheath  glabrous  or  slightly  scabrous  above,  usually  clasping,  seldom  ex- 
ceeding 5 'inches  in  length;  blade  elongated,  often  exceeding  1  foot,  usually  in- 
volute, scabrous;  ligule  about  1  line  long,  truncate,  margin  minutely  ciliate. 
Leaves  of  the  stem  2  to  4,  similar;  sheaths  mostly  long  and  imbricated,  often  ex- 
ceeding 1  foot. 

Inflorescence  paniculate.  Panicle  spike-like,  6  to  12  inches  long,  commonly  i 
to  |  inch  in  diameter,  usually  sheathed  at  the  base;  branches  1  inch  long  or  less, 
appressed  to  the  terete  scabrous  rachis.  Branches  and  pedicels  scabrous. 

Spikelets  lanceolate,  narrowed  at  the  base,  terete,  acute  at  the  apex,  l£  to  2  lines 
long,  borne  singly  on  the  pedicels,  rachilla  pilose  between  the  second  and  third 
glumes. 

Glumes  3;  first  and  second  nearly  equal,  lanceolate-oblong,  obtuse  or  acute, 
1 -nerved,  scabrous,  two-thirds  the  length  of  thespikelet;  third  (flowering)  broadly 
lanceolate  when  spread  open,  acute,  3-  to  5-nerved,  scabrous,  with»neither  awn  or 
mucro,  hyaline  below,  usually  lead-colored  above. 

Flower  hermaphrodite,  single.  Palet  lanceolate,  equaling  its  glume,  2-nerved, 
acute  at  the  apex.  Stamens  3;  anthers  linear,  about  1  line  long.  Stigmas  short, 
long-fimbriate. 

Grain  not  seen.     Rachilla  probably  disarticulating  above  the  second  glume. 

PLATE  XXVIII;  a  and  b,  spikelet,  opened  and  the  parts  separated;  c,  same, 
closed  and  facing  in  the  opposite  direction.  The  ovary  is  more  than  five  times  too 
long,  and  was  probably  drawn  from  a  half  matured  specimen. 

This  is  a  coarse  grass  growing  in  dense  clumps,  and  is  also  sometimes  called 
saccato.  It  does  not  extend  far  northward. 


EPICAMPES  RIGENS,  Benth. 


CHLORIS  ALBA  Presl. 

Plant  annual. 

Root  slender,  numerous. 

Culms  branching  from  the  base  and  lower  axils,  procumbent  at  the  base,  rarely 
rooting  at  the  lower  nodes,  glabrous,  commonly  1|  to  3  feet  high,  often  less. 

Leaves  4  to  8  on  the  stem;  sheaths  glabrous,  more  or  less  bladdery-inflated, 
often  loose,  usually  not  contiguous;  blades  1  to  2$  lines  broad,  9  inches  long  or 
much  shorter,  flat,  glabrous  beneath,  scabrous  on  the  margins  and  above. 

Inflorescence  a  sheathed  or  pedunculate  cluster  of  sessile  spikes.  Spikes  5  to 
15,  2  to  3|  inches  long,  only  slightly  spreading;  rachis  filiform,  terete,  straight, 
scabrous;  spikelets  closely  set,  sessile,  in  2  rows  along  one  side. 

Spikelets  compressed,  2-flowered;  lower  flower  hermaphrodite;  upper  staminate 
or  reduced  to  a  sterile  glume,  li  to  2  lines  long  (exclusive  of  awns  and  hairs). 

Glumes  4;  first  one-third  to  one-half  the  length  of  the  spikelet,  lanceolate, 
acute  or  obtuse,  membranaceous,  1-nerved,  nerve  scabrous;  second  about  two-thirds 
the  length  of  the  spikelet,  lanceolate,  acute,  membranaceous,  its  single  nerve  scab- 
rous and  produced  into  an  aristate  point  nearly  reaching  the  apex  of  the  spikelet; 
rachilla  pilose  between  the  second  and  third  glumes;  third  (flowering)  obovate, 
compressed,  apex  narrowed  making  the  glume  hooded,  pilose  in  irregular  areas 
on  the  back,  or  glabrous,  the  margin  short-pilose  below,  and  on  either  margin 
near  the  apex  long-pilose,  hairs  two-thirds  as  long  as  the  spikelet,  apex  of  the 
glume  produced  into  a  slender,  scabrous,  straight,  not  twisted  awn  two  to  three 
times  the  length  of  the  spikelet;  sterile  glume  similar  in  shape  to  the  flowering 
glume,  but  smaller  and  glabrous,  with  a  nearly  equal  awn.  Rudiment  of  a  third 
flower  sometimes  present. 

Flower  hermaphrodite.  Palet  oblanceolate,  2-nerved,  margins  folded  inward. 
Stamens  3;  anthers  small,  sagittate-lanceolate,  i  line  long;  stigmas  small,  cylin- 
drical. Flower  of  sterile  glume  sometimes  wanting,  sometimes  represented  only 
by  a  palet,  rarely  by  stamens  also. 

Grain  narrowly  fusiform,  acute  at  both  ends,  f  to  1  line  long,  inclosed  in  the 
flowering  glume,  the  rachilla  disarticulating  above  the  second  glume. 

PLATE  XXIX;  a  and  b,  spikelet,  rachilla  broken  at  the  point  of  disarticula- 
tion,  and  the  parts  spread  open.  In  a  the  shorter  glume  should  be  on  the  right  and 
below,  the  longer  on  the  left.  In  6,  the  sterile  glume  and  the  rudiments  of  a 
third  flowering  glume  are  shown. 

This  species  is  common  in  the  southern  parts  of  this  region,  and  still  more 
common  in  Mexico. 


CHLORIS  ALBA,  Presl. 


No.  30. 
CHLORIS  CILIATA  Swartz,  var.  TEXAN  A  Vasey  n.  var. 

Plant  annual. 

Culms  tufted,  erect,  compressed,  glabrous,  branching  only  at  the  base. 

Leaves  of  the  stem  3  to  5;  sheaths  not  contiguous,  glabrous,  conspicuously 
striate,  rarely  loose;  blades  1  to  2£  lines  wide,  9  inches  or  less  long,  flat  or  some- 
times involute,  scabrous  on  the  margins. 

Inflorescence  a  short-pedunculate  cluster  of  4  to  6  sessile  spikes.  Spikes  2|  to  3| 
inches  long,  slightly  spreading;  spikelets  in  2  rows  along  one  side  of  the  slen- 
der scabrous  rachis,  inserted  in  each  row  at  intervals  of  about  f  line. 

Spikelets  1  to  1|  lines  long,  truncate-cuneate,  compressed. 

Glumes  4;  first  and  second  lanceolate-oblong,  acute,  1-nerved  (nerves  scabrous 
on  the  back)  first  about  one-half  the  length  of  the  spikelet,  second  nearly  as  long 
as  the  spikelet  and  with  a  short  scabrous  point;  third  (flowering)  glume  very 
broadly  oblong,  acute,  3-nerved  (2  lateral  nerves  nearly  marginate),  sharply 
folded  down  the  middle,  densely  long-pilose  on  the  median  nerve  and  on  the  middle 
third  of  the  marginal  nerves,  bearing  below  the  apex  a  short  straight  scabrous  awn 
about  one-half  the  length  of  the  spikelet;  fourth  (sterile)  glume  broadly  truncate- 
cuneate,  3-nerved,  glabrous,  folded  down  the  middle,  awned  like  the  flowering 
glume.  2  or  3  additional  successively  smaller  rudiments  of  glumes,  of  similar  shape 
but  unawued,  often  present.  Rachilla  short-pilose  between  the  second  and  third 
glumes. 

Flower  single,  hermaphrodite.  Palet  ovate,  acute,  2-nerved,  margins  folded 
inward,  nerves  ciliate,  body  of  the  palet  curved  inward  transversely  and  outward 
longitudinally.  Stamens  3;  anthers  ovate-sagittate,  \  line  long.  Stigmas  cylin- 
drical. 

Grain  not  seen.     Rachilla  when  mature  disarticulating  above  the  second  glume. 

PLATE  XXX;  a,  spikelet;  b  and  c,  same,  with  the  parts  spread  open  and  the 
rachilla  broken  at  the  point  of  disarticulation. 

This  variety  (?)  differs  conspicuously  from  the  type  in  the  longer  spikes;  but  we 
lack  authentic  specimens  for  comparison.  It  was  collected  near  Brownsville,  Texas, 
and  probably  is  not  found  far  from  the  coast. 


CHLOEIS  CILIATA,  Swartz,  Far. 


No.  31. 
CHLORIS  CUCULLATA  Bischoff. 

Plant  annual. 

Culms  erect,  at  the  base  procumbent,  9  to  24  inches  high,  somewhat  compressed 
or  nearly  terete,  glabrous,  branched  only  at  the  base. 

Leaves  of  the  root  numerous ;  sheaths  3  inches  long  or  less,  glabrous,  compressed, 
glaucous,  with  conspicuous  membranaceous  margins,  the  outer  loose ;  blades  1  to 
9  inches  long,  f  to  H  lines  wide,  usually  longitudinally  folded,  glaucous,  scabrous 
on  the  midrib  margins  and  upper  surface,  apex  abruptly  acute  or  mucronate ;  lig- 
ule  about  |  line  long,  membranaceous,  minutely  ciliate  at  the  apex.  Leaves  of  the 
stem  2  to  4,  similar  to  those  of  the  root ;  sheaths  not  contiguous,  upper  more  or 
less  inflated ;  blade  of  the  uppermost  leaf  often  very  small. 

Inflorescence  a  more  or  less  long-peduncled  cluster  of  sessile  spikes.  Spikes  7  to 
16,  1  to  2  inches  long;  spikelets  borne  in  2  rows  along  one  side  of  the  slender, 
scabrous  rachis,  inserted  in  each  row  at  intervals  of  about  f  line. 

Spikelet  slightly  less  than  1  line  long,  of  the  form  of  an  equilateral  triangle. 

Glumes  4 ;  first  and  second  oblong-lanceolate,  hyaline,  1-nerved,  nerve  green 
and  usually  glabrous,  apex  acute  or  obtuse,  first  about  ^  line  long,  second  \  to  f 
line  ;  third  (flowering)  glume  compressed,  3-nerved,  short-ciliate  on  the  keel  and 
intramarginal  nerves,  otherwise  glabrous,  bearing  below  the  apex  a  minute  scab- 
rous awn  \  line  long,  each  half  of  the  glume  oval,  bluntly  acute  at  either  end; 
fourth  (sterile)  glume  compressed,  glabrous,  awned  similarly  to  the  third,  5-  to  7- 
nerved,  the  lateral  nerves  distant  from  the  middle  nerve,  each  half  of  the  glume 
wedge-truncate,  as  broad  as  long,  apex  and  free  margin  involute.  Rudiment  of  a 
fifth  glume  usually  present. 

Flower  single,  hermaphrodite.  Palet  oval,  2-nerved,  apex  broadly  notched, 
nerves  ciliate,  intramarginal,  the  narrow  margins  inflexed.  Stamens  3 ;  anthers 
ovate,  sagittate,  minute.  Stigmas  short,  cylindrical. 

Grain  oblong,  acute  at  both  ends,  loosely  inclosed  in  its  glume  and  palet,  upper 
portion  of  the  spikelet  falling  away  together,  rachilla  disarticulating  above  the 
second  glume. 

PLATE  XXXI ;  a  and  6,  spikelet,  the  parts  opened  and  the  rachilla  broken  at  the 
point  of  disarticulation.  The  flowering  glume  (to  the  left  in  b)  should  be  ciliate  on 
the  back  and  the  awn  scabrous.  The  sterile  glume  (on  the  right  in  b)  should  be 
similarly  awned,  and  the  palet  should  be  ciliate  on  the  margins. 


CHLORIS  CUCULLATA,  Bisch. 


No.  32. 
CHLORIS  GLAUCA  Vasey. 

Plant  annual,  entirely  glabrous. 

Culm  single,  erect,  2  to  4  feet  high,  glabrous,  unbranched. 

Leaves  of  the  root  numerous;  sheath  very  closely  compressed,  equitant,  widely 
diverging,  about  3  lines  wide  when  folded,  8  inches  or  less  long,  continuing  into 
the  blade  with  a  mere  slight  contraction  at  the  mouth;  blade  folded  below,  flat 
above,  keeled,  3  to  4  lines  wide,4to  12  inches  long,  abruptly  obtuse  at  the  apex;  second, 
third,  and  usually  fourth  iiiternodes  of  the  culm  very  short,  their  leaves  similar  to 
those  of  the  root  and  appearing  to  start  from  the  first  node  of  the  stem.  Suc- 
ceeding leaves  1  or  2,  with  longer  close  sheaths;  blade  nearly  wanting. 

Inflorescence  an  erect,  pedunculate,  iimbellate  cluster  of  8  to  15  spikes.  Spikes 
3  to  5  inches  long;  rachis  triangular,  scabrous;  this  and  the  first  and  second  glumes 
greenish  straw-color,  remainder  of  the  spikelets  very  dark  brown  or  black. 

Spikelets  in  2  rows  on  one  side  of  the  rachis,  inserted  alternately,  those  in 
each  row  at  intervals  of  about  £  line,  1  line  long. 

Glumes  4;  first  f  line  long,  ovate-lanceolate,  acute,  insequilateral,  with  1 
rigid  scabrous  nerve;  second  1  line  long,  linear,  notched  at  the  apex,  nerved 
like  the  first,  nerve  produced  into  a  short  deflexed  scabrous  mucro,  mucros  sec- 
und  along  the  edge  of  the  spike;  third  (flowering)  glume  compressed,  scabrous 
toward  the  apex,  each  half  oblong,  acute;  fourth  (sterile)  glume  obovate,  truncate, 
scabrous  along  the  upper  margin,  rolled  into  a  tube. 

Flower  single,  hermaphrodite.  Palet  oblanceolate-oblong,  notched  at  the 
acute  apex,  2-nerved,  with  additional  inflexed  membranaceous  margins.  Stamens  3 ; 
anthers  oblong-linear,  \  line  long,  notched  at  the  apex.  Stigmas  short  cylindrical. 

Grain  oblong,  acute  at  either  end,  triangular  in  cross-section ;  rachilla  disar- 
ticulating above  the  second  glume. 

Plate  XXXII ;  a  and  b,  spikelet  opened  to  show  the  parts;  rachilla  broken  at 
the  point  of  disarticulation.  The  leaf  belonging  to  the  uppermost  node  of  the 
stem  is  not  shown. 

NOTE. — This  species  was  inserted  here,  by  mistake,  instead  of  Chloris  Swart- 
ziana  Doell.  (Chloris petrc&a  Swz.),  which  occurs  in  Texas  near  the  coast.  It  is 
much  less  robust,  with  narrower  leaves,  fewer  spikes  (3  to  5),  and  some  difference 
in  the  flowers.  It  is  possible,  however,  that  both  species  may  occur,  although 
Chloris  glauca  is  principally  known  from  Florida. 


CHLORIS  GLAUCA,   Vasey. 


No.  33. 
CHLORIS   VERTICILLATA  Nuttall. 

Plant  annual. 

Culms  single  or  few  in  a  tuft,  10  to  16  inches  high,  branching  at  the  base,  the 
branches  commonly  sterile,  spreading  below. 

Leaves  sometimes  obtuse,  but  usually  acuminate,  at  the  apex;  sheath  provided 
at  the  throat,  especially  near  the  margin  within,  with  a  few  long  slender  hairs. 

Inflorescence  short-pedunculate  or  sometimes  sheathed  below.  Spikes  8  to  14, 
4  to  6  inches  long,  often  naked  at  the  base,  clustered  at  the  apex  of  the  stem  and 
at  that  point  hairy,  or  a  few  verticillate  branches  in  1  or  2  series  on  a  prolon- 
gation of  the  axis.  Spikelets  arranged  in  2  rows  on  one  side  of  the  slender,  sca- 
brous rachis,  at  intervals  in  each  row  of  about  2  to  2£  lines. 

Spikelet  about  1-J  lines  long,  cuneate-obovate,  compressed. 

Glumes  4;  first  and  second  with  1  scabrous  nerve,  first  as  long  as  the  spike- 
let,  lanceolate,  aristate-acute;  second  with  a  longer  point,  exceeding  the  spikelet; 
third  (flowering)  glume  3-nerved,  bearing  a  slender  scabrous  awn  (4  to  5  lines  long) 
below  the  apex,  broadly  oblong,  bluntly  acute  at  each  end,  short-pilose  on  the  mid- 
rib and  intramarginal  nerves,  elsewhere  glabrous;  fourth  (sterile)  glume  broadly 
obovate,  nearly  truncate,  3-nerved,  glabrous,  with  an  awn  3  to  4  lines  long;  small 
fifth  glume,  similar  in  form  to  fourth,  usually  present. 

Flower  sometimes  single,  hermaphrodite.  Palet  narrowly  oblong,  2-nerved, 
nerves  ciliate  and  margins  inflexed.  Stames  3;  anthers  minute.  Stigmas  cylin- 
drical. Flower  often  present  in  the  axil  of  the  fourth  glume,  sometimes  her- 
maphrodite, sometimes  reduced  to  an  empty  palet. 

Grain  not  seen. 

PLATE  XXXIII;  a,  spikelet  opened  to  show  the  parts,  the  rachis  broken.  The 
figure  represents  an  unexpanded  panicle;  when  expanded,  the  branches  are  spread 
at  right  angles  with  the  axis. 


CHLOEI8  VERTICILLATA,  Nutt. 


No.  34. 
BOUTELOUA. 

The  genus  Bouteloua,  which  includes  those  grasses  popularly  called  grama  grass, 
is  a  very  large  one  in  the  Southwest,  embracing  many  species,  both  annuals  and 
perennials.  They  are  nearly  all  nutritious  and  valuable  for  pasturage.  The  gen- 
eral characters  of  the  inflorescence  are  as  follows:  1  or  several-flowered  spikes 
single  at  the  apex  of  the  culm,  or  several  disposed  in  a  raceme ;  these  spikes 
closely  crowded  or  loosely  imbricated  with  spikelets  arranged  on  one  side  of 
the  rachis  in  2  rows  ;  spikelets  usually  consisting  of  1  perfect  flower  and  a 
pedicel  (bearing  1  to  3  stiff  awns,  and  usually  a  few  imperfect  glumes  with  the 
awns)  ;  one  or  two  additional  imperfect  flowers  rarely  present  in  the  spikelet ; 
flowering  glumes  variously  lobed  at  the  apex,  lobes  terminating  with  awns.  The 
several  species  present  a  great  diversity  in  the  details  of  these  general  features. 


BOUTELOUA  ARENOSA  Vasey. 

Plant  annual.     Roots  few,  fibrous. 

Culms  in  tufts,  erect  or  decumbent,  simple  or  geniculate  and  branching  below, 
slender,  6  to  10  inches  long. 

Leaves  sparse;  sheath  loose,  shorter  than  the  internode,  striate ;  ligule  conspicu- 
ous, strongly  ciliate  ;   blade  i  to  1  line  wide,  1  to  2  inches  long,  long-acuminate. 

Panicle  2  to  2£  inches  long,  composed  of  3  or  4,  mostly  one-sided  sessile 
spikes,  i  to  f  inches  long,  erect,  or  somewhat  recurved,  consisting  of  about  20 
spikelets  arranged  alternately  on  the  narrow  flattened  rachis. 

Spikelets  imbricated,  each  with  1  perfect  and  1  rudimentary  flower,  about 
3  lines  long  including  the  awns. 

Empty  glumes  thin,  smooth,  1-nerved,  oblong-lanceolate,  1  to  L-j  lines  long, 
upper  usually  the  longer,  both  acute  and  sometimes  toothed  at  the  apex  and  ter- 
minated with  a  short  awn;  flowering  glume  woolly  externally,  dividing  into  2 
lateral  and  1  central  awn,  body  about  1  line  long,  extending  into  2  narrow 
teeth  or  lobes  rather  shorter  than  the  awns,  lateral  awns  nearly  2  lines  long,  cen- 
tral one  somewhat  shorter. 

Palet  narrower  than  its  glume,  2-  to  4-toothed,  2-nerved,  nerves  extended  into 
awns.  Imperfect  flower  inclosed  by  the  flowering  glume,  consisting  of  3  long 
awns  at  the  summit  of  a  short  hairy  pedicel,  2  of  the  awns  having  each  a  rudi- 
mentary scale  at  the  base. 

PLATE  XXXIV;  a,  spikelet  enlarged  ;  &,  empty  glumes;  c,  flowering  glume; 
d,  palet ;  e,  imperfect  flower. 

The  specimens  were  from  loose  sandy  soil,  at  Guaymas  on  the  Gulf  of  California. 


BOUTELOUA  ARENOSA,   Vasey. 


No.  35. 
BOUTELOUA    ARISTIDOIDES  Thurber. 

Plant  annual. 

Culms  erect  or  decumbent,  frequently  geniculate  and  branching,  slender,  grow- 
ing in  clusters,  very  variable  in  development,  often  fruiting  when  a  few  inches  high, 
sometimes  reaching  2  feet  in  height. 

Leaves  with  blades  varying  with  the  size  of  the  plant  from  1  to  3  or  4  inches  in 
length,  very  narrow,  erect,  finely  pointed  ;  sheath  short,  striate,  smooth  except  a 
few  long  hairs  at  the  top ;  ligule  a  short,  ciliate  ring. 

Panicles  racemose,  terminal  and  lateral,  mostly  2  to  4  inches  long,  and  consist- 
ing of  10  to  12  narrow,  nearly  sessile  flower-spikes,  these  generally  one-sided,  in 
age  spreading  or  horizontal,  or  even  reflexed.  Spikes  £  to  f  inch  long,  on  short 
hairy  pedicels ;  each  spike  with  2  to  4  closely  appressed  spikelets,  lowest  with- 
out the  imperfect  flower  and  pedicel. 

Spikelets  3  lines  long. 

Lower  empty  glume  linear  or  awl-shaped,  one-half  as  long  as  the  stouter  upper 
one  ;  this  3  lines  long,  1-nerved,  somewhat  pubescent  on  the  back ;  flowering  glume 
linear-lanceolate,  acuminate,  3-nerved,  3-toothed  at  the  apex. 

Palet  a  little  shorter,  2-nerved,  2-toothed.  Rudimentary  flower  consisting  of 
3  long  awns  on  a  short  pedicel,  wanting  in  the  lower  spikelet. 

PLATE  XXXV;  a,  spike;  b,  empty  glumes  ;  c,  flowering  glume;  d,  flowering 
glume  of  the  lowest  spikelet;  e,  palet ;  /,  rudiment. 

This  species  springs  up  in  great  abundance  after  the  summer  rains,  and  for  a 
short  time  furnishes  a  large  amount  of  food  for  stock  on  the  ranges.  It  is  one  of 
the  so-called  six-weeks  grasses. 


BOUTELOUA  ARISTIDOIDES,  Thurb. 


No.  36. 
BOUTELOUA   BURKEI   Scribner. 

Eootstock  short,  strongly  rooted,  thickly  covered  with  the  crowded  culms. 

Culms  slender,  4  to  8  inches  high,  with  3  to  4  nodes  each. 

Leaves  mostly  crowded  at  the  base,  small,  -J  to  !-£  inches  long,  -£  line  wide;  ligule 
very  short,  ciliate  ;  sheaths  narrow,  mostly  shorter  than  the  internodes. 

Inflorescence  racemose-spicate,  about  one-third  the  length  of  the  plant,  con- 
sisting of  about  5  spikes  horizontal  or  even  reflexed  in  age.  Spikes  \  to  f  inch 
long,  of  10  to  15  spikelets,  arranged  in  2  rows  on  one  side  of  the  rachis.  Spikelets 
about  3  lines  long  including  the  awns. 

Empty  glumes  2,  lanceolate,  1-nerved,  smooth,  nearly  equal ;  body  of  the 
flowering  glume  less  than  1  line  long,  nearly  as  broad,  pubescent  on  the  back,  divid- 
ing into  3  lobes  extended  into  awns  ; 

Palet  narrow,  2-nerved,  2-dentate  at  apex  ;  imperfect  flower  consisting  of  3 
awns  on  a  short,  smooth  pedicel. 

PLATE  XXXVI;  a,  spike;  6,  spikelet;  c,  empty  glumes;  d,  flowering  glume; 
e,  palet ;  /,  imperfect  flower. 

This  species  is  closely  related  to  B.  trifida,  which  is  somewhat  larger,  the  empty 
glumes  narrower  and  unequal,  and  the  flowering  glume  longer  and  smooth. 


d          e 


A.M.-,.  *Co  !.,«,    B.Ui. 


BOUTELOUA  BUKKEI,  Scrib. 


No.  37. 
BOUTELOUA   ERIOPODA   Torrey. 

Perennial,  strongly  rooted. 

Culms  rather  weak,  straggling,  often  decumbent  and  rooting  at  the  lower 
joints,  1  to  3  feet  long,  lower  part  of  the  culm  and  sheaths  woolly-pubescent,  par- 
ticularly near  the  roots. 

Leaves  of  the  stem  5  or  6;  blades  narrow,  short,  2  to  3  inches  long,  1  to  2  lines 
wide,  or  from  proliferous  shoots,  sometimes  from  4  to  6  inches  long;  sheaths  much 
shorter  than  the  internodes. 

Panicle  racemose,  3  to  6  inches  long,  composed  of  5  or  6  one-sided  nearly 
sessile  spikes;  these  1  to  2  inches  long,  erect-spreading,  each  containing  15  to  20 
spikelets. 

Spikelets  each  with  1  perfect  and  1  imperfect  flower,  4  to  5  lines  long,  includ- 
ing the  awns. 

Perfect  flower:  outer  empty  glumes  lanceolate,  acuminate,  1-nerved,  very 
unequal,  lower  about  one-half  the  length  of  the  upper;  flowering  glume  pubescent 
at  the  base,  otherwise  smooth,  faintly  3-nerved,  linear-oblong,  3  lines  long,  with  2 
narrow  teeth  at  the  apex  and  a  middle  one  prolonged  into  an  awn  1  line  long; 
palet  nearly  as  long,  narrower,  2-nerved,  finely  2-toothed  at  the  apex. 

Imperfect  flower  consisting  of  3  slender  awns  on  a  pedicel,  with  a  narrow  tuft 
of  hair  below  the  united  awns;  whole  4  to  5  lines  long. 

PLATE  XXXVII:  1,  plant  of  matured  size;  2,  panicle  of  a  smaller  plant;  a, 
empty  glumes;  b,  flowering  glume,  palet,  stamens,  pistil,  and  imperfect  flower. 

This  is  the  common  black  grama  grass  of  southern  New  Mexico  and  Arizona, 
and  is  the  most  valuable  grass  of  the  mesas. 


No.  38. 
BOUTELOUA   HAVARDII  Vasey. 

Eootstock  short,  roots  very  strong. 

Culms  erect,  1  to  2  feet  high,  leafy  at  the  base,  sparsely  leafy  above. 

Lower  leaves  with  the  blades  crowded,  concave,  rigid,  rough  on  the  margins 
and  beneath,  ciliate  with  short,  rather  distant,  hairs;  lower  sheaths  short,  loose, 
striate;  ligule  a  ring  of  short  hairs;  upper  sheaths  becoming  much  longer,  blades 
shorter. 

Panicle  1-J  to  2-£  inches  long,  composed  of  5  to  7  short,  thickish,  approximate 
spikes,  with  short,  woolly  pedicels;  spikes  about  £  inch  long,  erect  or  spreading, 
consisting  of  9  to  13  crowded  spikelets  on  a  hairy  rachis. 

Spikelets  3  inches  long  beside  the  awns  of  the  sterile  flower,  hairy. 

Empty  glumes  lanceolate,  acuminate,  unequal;  upper  one  3  lines  long,  with  a 
thick  midrib,  pungent,  twice  as  long  as  the  lower,  both  beset  on  the  back  with 
long  white  hairs;  flowering  glumes  oblong-lanceolate,  3-nerved,  3  lines  long, 
3-toothed  at  the  apex,  strongly  ciliate  on  the  margins. 

Palet  about  as  long  as  its  glume,  2-nerved,  2-toothed  at  the  apex.  Imperfect 
flower  composed  of  3  stout  awns,  5  to  6  lines  long,  these  hairy  below  and  united  at 
the  summit  of  a  naked  pedicel. 

PLATE  XXXVIII:  a,  spikelet;  b,  flowering  glume;  c,  palet;  d,  imperfect 
flower. 


BOUTELOUA  HAVARDII,  Vasey. 


No.  39. 
BOUTELOUA    HIRSUTA   Lagasca. 

Roots  fibrous,  csespitose. 

Culms  erect,  simple,  or  in  var.  minor  geniculate  and  branching  below. 

Leaves  usually  short,  1  to  4  inches  long,  narrow,  sometimes  ciliate  on  the  mar- 
gins, produced  into  a  long,  fine  point;  lower  sheaths  short,  upper  longer,  and  with 
shorter  blades. 

Panicle  consisting  of  from  1  to  3  erect  spikes,  £  to  1|  inches  long. 

Spikelets  about  3  lines  long,  hirsute,  densely  crowded  on  one  side  of  the 
smooth  rachis;  this  extended  in  a  naked  point  beyond  the  flowers. 

Empty  glumes  unequal,  lower  about  1  line  in  length,  narrowly  lanceolate, 
acute,  smooth;  upper  about  2|  lines  long,  lanceolate,  acuminate,  awn-pointed,  with 
a  row  of  dark  or  black  glands  on  either  side  of  the  midrib,  each  one  emitting  a 
long  hair;  flowering  glume  2$  lines  long,  including  the  awns,  nearly  smooth, 
oblong,  lower  half  entire,  upper  divided  into  3  lobes,  each  terminating  in  a  short 
awn. 

Palet  narrower,  entire,  2-nerved. 

Imperfect  flower  on  a  short,  smooth  pedicel,  consisting  of  3  awns  and  3  scales, 
awns  extending  a  little  beyond  the  perfect  flower. 

PLATE  XXXIX:  1,  typical  plant;  2,  var.  minor;  3,  var.  major;  a,  empty 
glumes;  6,  perfect  and  imperfect  flowers;  c,  flowering  glume. 

Several  forms  are  grouped  under  this  species;  the  three  principal  ones  being 
here  illustrated.  The  species  has  a  wide  range,  from  Mexico  northward  to  Mon- 
tana and  east  of  the  Mississippi  in  Illinois  and  Wisconsin.  It  is  by  no  means  as 
plentiful  as  B.  oligostachya,  and  is  less  valuable  as  a  forage  grass. 


BOUTELOUA  HIR8UTA,  Lag. 


No.  40. 
BOUTELOUA  HUMBOLDTIANA  Kunth. 

Culms  erect,  rarely  branching,  firm,  15  to  20  inches  high,  smooth,  leafy  below. 

Leaves:  sheath  open,  striate,  shorter  than  the  internodes;  ligule  inconspic- 
uous; blade  1  to  2  lines  wide,  3  to  6  inches  long,  scabrous  especially  on  the  mar- 
gins, often  sparsely  ciliate  below. 

Inflorescence  racemose,  3  to  4  inches  long,  consisting  of  about  7  to  9  one-sided, 
short- pedicelled  spikes,  lower  ones  -£  inch  or  more  distant,  others  gradually  shorter; 
spikes  about  $  inch  long,  each  consisting  of  7  to  9  smooth  spikelets,  somewhat 
loosely  overlapping  each  other. 

Spikelets  about  |  inch  long,  including  the  awns,  smooth,  consisting  of  2  to  3 
flowers,  upper  male,  others  perfect,  or  the  lower  2  fertile  and  the  upper  reduced 
to  an  awn. 

Empty  glumes  nearly  equal,  3  to  4  lines  long,  keeled,  lanceolate,  acute;  flower- 
ing glume  of  the  lower  flower  4  lines-  long,  lanceolate,  3-nerved,  3-toothed,  at  the 
apex  of  the  second  flower  similar,  but  with  the  teeth  extended-  into  long  awns  (2 
to  3  lines  long). 

Palet  nearly  as  long  as  the  glume,  2-nerved,  2-toothed  at  the  apex.  Third 
flower  when  present,  sometimes  with  awns  still  longer,  or  imperfect  or  reduced. 

PLATE  XL:  a,  spikelet;  6,  empty  glumes;  c,  flowering  glume  of  the  fertile 
flower;  d,  palet  of  the  fertile  flower;  c',  flowering  glume  of  the  second  flower;  d', 
palet  of  the  second  flower.  The  sterile  flower  reduced  to  a  small  pedicel  is  seen  in  a. 

It  is  doubtful  whether  this  plant,  which  has  passed  under  the  name  B.  Hum- 
boldtiana,  is  really  identical  with  that  described  by  Kunth.  Our  plant  is  more 
probably  a  form  of  B.  bromoides  Lag.  In  range  it  seldom  extends  north  of  New 
Mexico. 


c       d 


BOUTELOUA  HUMBOLDTIANA,  Kunth. 


No.  41. 
BOUTELOUA   OLIGOSTACHYA  Torrey. 

Culms  caespitose  from  a  short  thick  rootstock  extending  into  a  thick  close 
mat,  slender,  smooth,  erect,  1  to  2  feet  high. 

Leaves  mostly  near  the  ground;  blade  short,  curled,  in  moist  situations 
becoming  slender  and  longer,  very  narrow,  attenuate  into  a  slender  point;  sheath 
shorter  than  the  internodes,  close;  ligule  very  short,  ciliate. 

Inflorescence  consisting  of  1  to  3  spikes,  densely  crowded  with  flowers  on  one 
side  of  the  rachis,  1  to  1|  inches  long,  usually  becoming  curved  and  spreading; 
rachis  narrow  and  sparsely  pubescent. 

Spikelets  very  numerous  (often  50  or  more),  in  2  rows  on  one  side  of  the 
rachis,  nearly  at  right  angles  with  it,  sparsely  pubescent,  sometimes  sparsely  glan- 
ular  on  the  keel,  about  3  lines  long,  containing  1  perfect  flower  and  1  rudimentary 
one. 

Empty  glumes  unequal,  awn-pointed;  lower  one-half  to  two-thirds  as  long  as 
the  upper,  thin;  upper  2%  to  3  lines  long,  purplish;  flowering  glume  lanceolate,  3 
lines  long,  including  the  awns,  hairy  on  the  back,  lobed  to  or  nearly  to  the  middle, 
middle  lobe  broad,  lateral  ones  very  narrow,  all  terminating  in  sharp  awns. 

Palet  nearly  equal  in  length  to  the  flowering  glume,  narrower,  2-toothed  at 
the  apex,  2-nerved.  Imperfect  flower  reduced  to  3  equal  awns,  with  1  or  2  scales 
at  the  base,  on  a  short  pedicel  having  a  tuft  of  white  hairs  at  the  top. 

PLATE  XLI:  land  2,  typical  plant;  3,  larger  form;  a,  empty  glumes;  b,  perfect 
and  imperfect  flowers;  c,  flowering  glume,  from  the  back. 

This  species  is  probably  more  widely  spread  than  any  other  of  the  family,  and  is 
the  one  which  constitutes  with  the  buffalo  grass  (Buchloe  dactyloides)  the  main 
vegetation  of  the  vast  plains  of  the  West. 


BOUTELOUA  OLIGO8TACHYA,  Torr. 


No.  42. 
BOUTELOUA   PROSTRATA  Lagasca. 

Annual.     Roots  fibrous. 

Culms  growing  in  small  depressed  tufts,  spreading  or  decumbent,  geniculate, 
leafy  to  the  top. 

Leaves  with,  short  narrow  blades  i  to  H  inches  long;  sheath  somewhat  loose, 
shorter  than  the  internodes,  striate;  ligule  inconspicuous. 

Inflorescence  a  single  terminal  spike,  generally  recurved,  f  to  1  inch  long, 
smooth. 

Spikelets  20  to  30,  in  rows  on  one  side  of  the  smooth  rachis,  nearly  3  lines  long, 
containing  1  perfect  and  2  imperfect  flowers. 

Empty  glumes  unequal;  lower  about  one-half  the  length  of  the  upper,  narrow; 
upper  about  2  lines  long,  ovate-lanceolate,  acute;  flowering  glume  smooth  or 
slightly  pubescent  on  the  back,  about  3  lines  long,  lower  half  broadly  oblong,  upper 
3-lobed,  3-awned,  middle  lobe  broadest  and  longest,  awns  stiff. 

Palet  nearly  2  lines  long,  denticulate  at  the  apex.  Imperfect  flower  reduced 
to  3  stiff  awns  with  1  or  2  scales  at  the  base,  on  a  short  pedicel  having  a  tuft  of 
white  hairs  at  the  top. 

PLATE  XLII:  a,  spikelet;  b,  empty  glumes;  c,  flowering  glume  from  the  back; 
d,  palet;  e,  imperfect  flower. 

This  annual  grass  is  widely  distributed  from  Mexico  to  Colorado,  prevailing 
in  bottom  lands,  where  it  frequently  mats  the  ground,  but  does  not  seem  to  be 
relished  by  cattle. 


BOUTELOUA  PROSTRATA,  Lag. 


No.   43. 
BOUTELOUA    RACEMOSA  Lagasca. 

Culms  in  close  tufts  from  a  strongly  rooted  rootstock  2  to  3  feet  high,  un- 
branched. 

Leaves  with  blades  4  to  12  inches  long,  2  lines  wide,  long-pointed,  scabrous; 
sheath  loose,  sparsely  pubescent;  ligule  short. 

Inflorescence  racemose,  6  to  9  inches  long,  composed  of  20  to  40  alternate, 
sometimes  one-sided,  short-pedicelled  or  nearly  sessile,  short  spikes,  these  spread- 
ing or  recurved,  sometimes  approximate,  sometimes  rather  distant;  common  rachis 
angular,  scabrous. 

Spikes  i  to  i  inch  long,  variable  in  thickness  and  fullness,  usually  of  about  5 
spikelets,  sometimes  reduced  to  2  or  3. 

Spikelets  2  to  3  lines  long  without  the  awns,  each  2-flowered. 

Empty  glumes  unequal;  lowest  one-third  shorter  than  the  upper,  narrow,  awn- 
pointed;  upper  2  lines  long  or  more,  ovate-lanceolate,  acute;  flowering  glume  about 
2  lines  long,  oblong,  smooth  or  somewhat  pubescent  on  the  margins,  3-nerved  near 
the  apex,  with  3  short  arms. 

Palet  as  long  as  its  glume,  2-nerved,  2-toothed  at  apex.  Imperfect  flower 
varying  in  development  from  a  few  rudimentary  awns  to  a  nearly  full-formed 
flower,  or  in  var.  aristosa  having  a  long-awned  flowering  glume  and  rudimentary 
scales. 

PLATE  XLIII:  above,  spike  of  about  3  spikelets;  below,  flower  showing  the 
empty  glumes,  perfect  and  imperfect  flowers. 

This  is  perhaps  more  widely  diffused  than  any  other  species,  ranging  from 
Mexico  to  British  America  and  east  of  the  Mississippi  in  Illinois,  Ohio,  and  several 
localities  in  eastern  New  York. 


BOUTELOUA  RACEMOSA,  Lag. 


No.    44. 
BOUTELOUA  RAMOSA  Scribner. 

Culms  many  from  a  crowded  short  rootstock,  strongly  rooted,  wiry-branched 
and  almost  woody  below,  slender,  above  leafy  to  the  inflorescence,  smooth. 

Leaves  with  blades  narrow,  short,  1  to  2  inches  long,  attenuated  to  a  fine  point; 
sheath  smooth,  striate,  with  a  few  long  hairs  at  the  top;  ligule  very  short. 

Inflorescence  consisting  usually  of  2  spikes,  1  to  1|  inches  apart  at  the  apex 
of  the  culm,  1  to  li  inches  long,  crowded  with  the  20  to  30  one-sided  spikelets. 

Spikelets  about  2£  lines  long,  with  1  perfect  and  1  imperfect  flower. 

Empty  glumes  smooth,  acute,  unequal;  lower  less  than  one-half  as  long  as  the 
upper,  narrow;  upper  lanceolate,  nearly  2  lines  long;  flowering  glumes  over  2  lines 
long,  lanceolate,  clothed  with  long  white  hairs  on  the  back  and  margins,  divided 
at  the  apex  into  3  sharply  awned  lobes. 

Palet  'narrower,  2-toothed  at  the  apex,  smooth.  Imperfect  flower  consisting  of 
3  awns  with  2  or  3  imperfect  glumes  at  their  base,  on  a  short  pedicel  densely 
hairy-tufted  at  the  apex. 

PLATE  XLIV:  a,  spikelet  spread  open  to  show  the  parts;  b,  empty  glumes;  c, 
flowering  glume;  d,  palet;  e,  imperfect  or  sterile  flower  and  its  pedicel. 

This  species  extends  from  northern  Mexico  to  Arizona  and  western  Texas. 


BOUTELOUA  RAMOSA,  Scrib. 


No.   45. 
BOUTELOUA  STRICTA  Vasey. 

Culms  2  to  2i  feet  high,  unbranched,  wiryv  stiffly  erect,  smooth;  base  clothed 
with  old,  persistent,  broad  sheaths. 

Leaves  few;  blade  erect,  rigid,  narrow,  becoming  setaceous-involute,  4  to  6 
inches  long,  scabrous  on  the  upper  surface;  lower  sheaths  broad,  loose,  smooth, 
and  short,  upper  becomjng  long  and  narrow  (3  to  4  inches  long) ;  ligule  very  short, 
ciliate. 

Inflorescence  about  4  inches  long,  consisting  of  5  or  6  erect  or  appressed, 
narrow,  one-sided  spikes,  these  i  to  1  inch  long,  densely  crowded  with  the  30  to  50 
spikelets. 

Spikelets  2  lines  long,  including  the  awns. 

Empty  glumes  unequal,  lanceolate,  acute;  lower  one-half  as  long  as  the  upper, 
nearly  smooth;  flowering  glume  2  lines  long,  pubescent  externally,  oblong-lanceo- 
late, 3-lobed  above,  lobes  awned,  lateral  lobes  a  little  shorter  than  the  the  central 
one. 

Palet  narrow,  nearly  as  long  as  its  glume,  2-nerved,  2-toothed  at  the  apex. 
Imperfect  flower  consisting  of  3  equal  awns,  with  2  or  3  imperfect  glumes  at  the 
base,  on  a  short  pedicel  with  a  tuft  of  soft  hairs  at  its  apex. 

PLATE  XLV;  a,  spikelet;  b,  empty  glumes;  c,  flowering  glume,  seen  from  the 
back;  d,  palet;  e,  imperfect  flower. 

This  species  differs  from  B.  oligostachya  in  its  more  wiry  culms,  more  rigid 
habit,  setaceous,  appressed  leaves,  and  dense,  appressed,  and  more  numerous  spikes. 


BOUTELOUA  STRICTA,  Vasey. 


No.  46. 
BOUTELOUA  TRIFIDA  Thurber. 

Culms  6  to  12  inches  long,  slender,  numerous,  crowded  on  a  short  rootstock;  base 
often  thickened,  covered  with  short,  broad  sheaths. 

Leaves;  blades  small,  radical  sometimes  2  or  3  inches  long,  those  of  the  culm 
often  reduced  to  i  inch,  smooth  or  sparsely  hairy;  sheath  shorter  than  the 
internode. 

Inflorescence  of  4  to  6  erect  or  somewhat  spreading  smooth  spikes,  with  about 
15  to  30  spikelets  rather  loosely  disposed. 

Spikelets  3  lines  long  including  the  awns,  containing  1  perfect  and  1  imperfect 
flower. 

Empty  glumes  slightly  unequal;  upper  l£  lines  long;  lower  one-fourth  shorter, 
smooth,  1-nerved;  flowering  glumes  narrow,  body  oblong,  smooth,  less  than  1 
line  long,  dividing  above  into  31ong-awned  lobes  (2  to  2^  lines  long). 

Palet  somewhat  shorter  and  narrower  than  its  glume,  2-toothed  at  the  apex. 
Imperfect  flower  reduced  to  3  slender  awns  slightly  enlarged  toward  the  base, 
on  a  short,  smooth  pedicel. 

PLATE  XLVI;  a,  spikelet;  b,  empty  glumes;  c,  flowering  glume;  d,  palet;  e, 
imperfect  flower. 

This  species  closely  resembles  B.  Burkei,  No.  36,  but  a  close  comparison  shows 
important  differences. 


BOUTELOUA  TBIFIDA,  Thurb. 


No.  47. 
BUCHLOE  DACTYLOIDES  Engelmann. 

Plant  usually  dioecious,  rarely  monoecious,  male  and  female  flowers  hetero- 
morphous. 

Culms  low,  4  to  8  inches  high,  in  dense  matted  tufts  or  patches,  interlaced  with 
stolons  from  a  few  inches  to  2  feet  long,  with  nodes  usually  2  to  3  inches  apart, 
these  developing  tufts  of  leaves  and  culms  and  often  taking  root. 
MALE  PLANT. 

Culms  slender,  erect  or  decumbent  at  base,  with  3  or  4.  leaves. 

Leaves.  Radical  4  to  6  inches  long,  1  line  or  less  wide,  acuminate,  smooth  or 
ciliate,  those  of  the  culm  %  to  2  inches  long;  upper  sheaths  often  longer  than  the 
blades,  loose;  ligule  and  throat  hairy. 

Inflorescence  a  terminal  panicle  of  2  to  4  approximate,  sessile  or  nearly  sessile 
spikes,  each  $  inch  or  less  in  length. 

Spikelets  5  to  10  or  more  in  2  ranks  on  one  side  of  the  rachis,  crowded,  each  2- 
or  3-flowered,  about  2  lines  long. 

Outer  empty  glumes  unequal,  1-nerved  or  the  lower  nerveless  and  minute,  the 
upper  one-half  to  two-thirds  as  long  as  the  spikelet,  oblong,  acute,  minutely  pub- 
escent; flowering  glumes  ovate,  2  lines  long,  membranaceous. 

Palet  ovate,  acuminate,  as  long  as  the  flowering  glumes,   2-nerved;  stamens 
3;  anthers  1  line  long,  linear. 
FEMALE  PLANT. 

Flowering  culms  short,  2  to  3  inches  high,  2  or  3  upper  leaves  clustered  at  the 
apex,  their  sheaths  inclosing  the  base  of  the  fertile  flowers. 

Inflorescence  consisting  of  1  to  3,  commonly  2,  short,  clustered  spikes,  each  3  to 
3£  lines  high,  and  of  about  5  spikelets;  rachis  of  the  spike  thickened. 

Spikelets  very  different  from  the  male  ones,  being  each  1-flowered  and  the  parts 
much  indurated  and  modified. 

Upper  empty  glume  indurated  and  cohering  at  the  base  with  the  enlarged 
rachis,  becoming  almost  woody,  divided  at  the  apex  into  3  or  more  rigid  teeth,  body 
convex  externally  and  infolding  the  flower  on  its  concave  side;  all  the  lower  empty 
glumes  (except  that  of  the  lowest  spikelet)  thin,  ovate,  acute,  1-nerved,  scale-like, 
on  the  inner  side  of  the  spikelet;  flowering  glumes  coriaceous,  3-nerved,  3-toothed 
at  apex. 

Palet  similar  in  texture  to  the  flowering  glume,  2-nerved,  24oothed,  inclosing 
the  large  ovary. 

PLATE  XLVII;  1,  male  plant ;  2,  female  plant ;  a,  male  spikelets ;  b,  empty 
glumes  of  same;  c,  flowering  glume  of  same;  d,  palet  of  same;  A,  female  spikelet; 
B,  upper  empty  glume  ;  C,  flowering  glume ;  D,  palet. 

This  grass  is  extensively  spread  over  all  the  region  known  as  the  Great  Plains. 
It  grows  in  extensive  patches,  spreading  largely  by  means  of  its  stolons  (similar  to 
those  of  Bermuda  grass),  which  are  sometimes  3  feet  long,  with  joints  every  few 
inches,  frequently  rooting  at  the  joints  and  forming  new  plants. 

The  flowsrs  of  the  two  sexes  are  usually  on  separate  plants,  but  sometimes 
both  kinds  are  found  on  different  parts  of  the  same  plant.  This  and  the  grama 
grass  (Bouteloua  oligostacliya]  are  the  principal  native  grasses  of  the  Plains,  and 
afforded  the  principal  subsistence  of  the  herds  of  buffalo  which  formerly  inhabited 
them.  It  is  rapidly  disappearing  before  the  advance  of  settlements. 


BUCHLOE  DACTYLOIDES,  Engl. 


No.  48. 
EREMOCHLOE    BIGELOVII  Watson. 

AND 

EREMOCHLOE  KINGII  Watson. 

1.  Eremochloe  Bigelovii. 

Culms  6  to  10  inches  high,  tufted,  branching  below,  smooth;  upper  portion 
naked,  except  2  or  3  small  approximate  leaves  below  the  panicle. 

Leaves  with  blades  |  to  H  inches  long,  setaceous,  striate,  pungent. 

Panicle  small,  1  inch  or  less  long,  simple,  or  with  1  or  2  short  branches, 
few-flowered. 

Spikelets  4-flowered;  2  lower  neutral;  third  perfect;  fourth,  or  uppermost, 
reduced  to  3  feathery  awns  on  a  short  pedicel. 

Empty  glumes  lanceolate,  smooth,  1-nerved,  about  3  lines  long. 

Sterile  flowers  consisting  each  of  a  flowering  glume  and  palet.  Flowering  glume 
2-lobed  to  the  middle,  densely  ciliate,  3-nerved,  with  a  slender  feathery  awn  between 
the  lobes,  these  tipped  with  a  short  awn;  palets  very  narrow,  smooth,  2-nerved, 
2-toothed  at  the  apex  or  very  rudimentary. 

Perfect  flower  with  the  flowering  glume  deeply  3-lobed,  lobes  extending  into 
stiff  ciliate  awns;  palet  two-thirds  as  long,  ovate,  abruptly  acuminate,  smooth, 
slightly  toothed  at  the  apex;  awns  3,  strongly  ciliate  and  united  at  the  apex  of  a 
short  smooth  pedicel;  a  linear  or  awn-like  scale  sometimes  attached  to  one  of  the 
sterile  palets. 

2.  Eremochloe  Kingii. 

Culm,s  low,  tufted,  1  to  2  inches  high. 

Leaves  crowded  at  the  base  of  the  stem;  sheath  dilated,  ciliate  at  the  margins 
and  apex,  persistent,  and  with  the  old  blades  cut  into  fibrillae;  blades  £  to  1  inch 
long,  rigid,  involute,  pungent. 

Panicle  short,  oblong,  sheathed  at  the  base  by  the  upper  leaf,  less  simple  than 
in  the  other  species. 

Spikelet  4-flowered;  flowers  as  in  E.  Bigelovii. 

Empty  glumes  4  lines  long,  acute,  smooth. 

Sterile  flowers  more  deeply  lobed;  middle  awn  membranaceous,  margined 
below. 

Perfect  flower  with  the  flowering  glume  deeply  3-lobed,  middle  lobe  narrower. 
Pedicel  and  awns  similar. 

PLATE  XLVIII;  1,  Eremochloe  Bigelovii;  a,  empty  glumes;  ft,  flowering 
glume;  c,  palet;  d,  pedicel  and  feathery  awns. 

2,  Eremochloe  Kingii;  e,  spikelet;  /,  empty  glumes;  g,  flowering  glume:  h, 
palet;  i,  pedicel  and  feathery  awns. 

Eremochloe  Bigelovii  was  found  on  the  bluffs  of  the  Rio  Grande  in  western 
Texas.  It  has  not  recently  been  collected. 

E.  Kingii  has  been  found  at  Peach  Springs,  Arizona,  and  at  several  places  in 
Nevada. 


1  EEEMOCHLOE  BIGELOVU,  S.   W.  2  EREMOCHLOE  KINGII,  S.  W. 


No.  49. 
MELICA  DIFFUSA  Pursh. 

Plant  perennial. 

Rootstock  not  seen.     Roots  slender. 

Culms  usually  single,  simple,  erect,  2  to  5  feet  high,  sometimes  shorter,  terete, 
glabrous. 

Leaves  of  the  stem  4  to  6;  sheaths  usually  distant,  closely  sheathing,  glabrous, 
margins  grown  together  to  within  about  £  inch  from  the  summit;  blade  5  to  8 
inches  long,  flat  and  reaching  4  lines  broad,  or  much  narrower  (1^  lines)  and  in- 
volute, smooth  or  scabrous  on  both  surfaces,  scabrous  points  on  the  upper  surface 
often  producing  hairs;  ligule  1  to  2  lines  long,  lacerate  when  old. 

Inflorescence  paniculate.  Panicle  long-pedunculate,  4  to  10  inches  long,  with 
3  to  7  nodes;  branches  2  at  each  node,  widely  spreading,  scabrous;  one  much  the 
smaller,  longer  not  exceeding  2^  inches;  rachis  terete,  nearly  scabrous.  Spikelets 
single,  on  slender  scabrous  pedicels  enlarged  and  villous  at  the  apex,  abruptly 
bent  just  below. 

Spikelets  narrowly  to  broadly  oblong,  slightly  compressed,  4£  to  6  lines  long, 
2-  to  4-flowered  with  rudiments  of  1  or  2  others  above. 

Glunl3s  with  green  nerved  body  and  membranaceous  margins  and  apex;  first 
5-nerved,  3  to  3^  lines  long,  oval,  apex  from  broadly  acute  to  acuminate;  second 
about  5-nerved,  4  to  5  lines  long,  oblong-oblanceolate,  apex  broadly  acute;  flower- 
ing glume  narrowly  oblong,  many-nerved,  acute,  scabrous  on  the  back,  1  to  3  nerves 
passing  through  the  membranaceous  margin  to  the  apex,  lowest  4  to  5i  lines  long, 
upper  successively  shorter.  >» 

Flowers  hermaphrodite.  Palet  oblong-oblanceolate  in  position,  ciliate  on  the 
2  nerves  above,  acute,  with  additional  inflexed  margins.  Stamens  3;  anthers  linear, 
about  li  lines  long.  Stigmas  not  seen. 

Grain  1  line  long,  narrowly  oblong,  obtuse  at  both  ends,  loosely  inclosed  be- 
tween the  glume  and  palet  (and  dropping  from  them  when  mature?);  outer  coat 
loose,  wrinkled,  and  shining. 

PLATE  LXIX;  a  and  b,  spikelet  enlarged  showing  the  parts,  rachilla  broker 
above  the  second  glume. 


MELICA  DIFFU3A,  Pursh. 


No.  50. 
MELICA  PORTERI  Scribner. 

Plant  perennial. 

Rootstock  slender,  creeping,  scales  distant.     Roots  very  slender. 

Culms  tufted,  slender,  erect,  2  to  3  feet  high,  unbranched,  glabrous. 

Leaves  of  the  stem  7  to  10;  sheaths  imbricated,  sparingly  backwardly  scabrous, 
margins  grown  together;  blades  6  to  12  inches  long,  upper  sometimes  shorter,  1 
to  2  lines  wide,  flat,  usually  somewhat  scabrous  beneath,  sparingly  pilose  above. 
Leaves  of  the  root,  with  their  sheaths,  early  decaying. 

Inflorescence  paniculate.  Panicle  terminal,  short-pedunculate,  8  to  12  inches 
long;  rachis  terete,  nearly  glabrous;  branches  spreading  in  anthesis,  afterwards 
erect,  3  inches  long  or  less,  scattered,  commonly  2  at  each  node,  one  much 
smaller  than  the  other.  Spikelets  borne  singly  on  slender  scabrous  pedicels  pilose 
and  abruptly  bent  at  the  apex. 

Spikelet  3-  to  5-flowered,  4  to  7  lines  long,  slightly  compressed,  linear-oblong, 
narrowed  at  base  and  apex. 

Glumes  with  green  nerved  body  and  broad  hyaline  margins  and  apex;  first 
ovate,  bluntly  acute,  2  to  3  lines  long,  1-  to  5-nerved,  middle  nerve  scabrous;  second 
similar,  one-third  longer,  7-to  9-nerved;  third  (flowering)  elliptical -oblong,  nar 
rowed  to  the  base  and  apex,  about  3  lines  long,  body  rather  coriaceous,  scabrous  on 
the  back,  with  about  7  principal  nerves  and  often  with  intermediate  slender 
ones,  all  converging  toward  the  apex  but  not  uniting  and  not  traversing  the 
hyaline  apex  of  the  glume. 

Flowers  hermaphrodite.  Palet  oblong-lanceolate  when  in  position,  acute, 
ciliate  on  the  2  nerves,  with  additional  inflexed  membranaceous  margins. 
Stamens  3;  anthers  linear,  1  line  long.  Stigmas  cylindrical. 

Grain  (mature?)  linear,  1  line  long,  dropping  naked  from  the  spikelet  when 
ripe;  pericarp  rather  loose,  wrinkled;  rachilla  not  disarticulating. 

PLATE  L;  a  and  6,  spikelet  opened  to  show  the  parts.  The  second  flower  at 
least  should  have  stigmas.  The  shorter  glume  in  a  is  the  outer  one. 


MELICA  PORTERI,  Scrib. 


U.S.  DEPARTMENT  OF  AGRICULTURE, 

DIVISION  OF  BOTANY. 

BTJLLETIlSr    No.    12. 


GRASSES  OF  THE  SOUTHWEST. 


PLATES  AND  DESCRIPTIONS 


GRASSES  OF  THE  DESERT  REGION  OF  WESTERN  TEXAS,  NEW  MEXICO, 
ARIZONA,  AND  SOUTHERN  CALIFORNIA. 


Part   II. 

By  DR.  GEO.  VASEY, 

BOTANIST,  DEPARTMENT  OF  AGRICULTUKK. 

ISSUED    DECEMBER,  1§91. 


PUBLISHED  BY  AUTHORITY  OF  THE  SECRETARY  OF  AGRICULTURE. 


WASHINGTON : 

GOVERNMENT  PRINTING  OFFICE. 

1891, 


NOTE. 

This  bulletin  constitutes  the  second  half  of  the  first  volume  of  a  work  entitled 
Illustrations  of  North  American  Grasses.  It  is  designed  to  continue  the  work  by 
a  second  volume  to  be  entitled  Grasses  of  the  Pacific  Coast. 


LETTER  OF  TRANSMITTAL 


WASHINGTON,  August  3,  1891. 

SIR:  I  have  the  honor  of  herewith  presenting  for  publication  the  manuscript 
of  the  second  part  of  the  Bulletin  on  the  "  Grasses  of  the  Southwest." 

GEORGE  VASEY, 

Botanist. 
Hon.  J.  M.  RUSK, 

Secretary  of  Agriculture. 


NTRODUCTION. 


This  second  part  of  the  Grasses  of  the  Southwest  presents,  like  the  first  part, 
plates  and  descriptions  of  50  species  of  grasses,  together  making  100. 

The  synonymy  of  such  as  have  had  several  names  is  briefly  given.  Most  of 
the  species,  however,  are  either  new,  or  so  little  known  that  they  have  received 
but  a  single  name.  The  drawings  were  made  by  Messrs.  Scholl,  Olszewski,  and 
Holm,  and  in  the  details  are  generally  very  accurate.  I  wish  to  express  my  obliga- 
tions to  Mr.  L.  H.  Dewey,  Assistant  Botanist,  for  important  assistance  in  describing 
the  species. 

GEO.  VASEY. 

AUGUST  3,  1891. 

6 


INDEX   OF    PLATES 


Plate. 

Aristida  purpurea •       7 

Chloris  Swartziaria     28 

Cottea  pappophoroidea 29 

1  )i|)lachue  fascicularis 41 

imbricata 42 

Reverchoni 43 

rigida 44 

viscida 45 

Elionurus  tripsacoidee 1 

Elynuis  Sitanion 50 

Eragrostis  curtipedicellata 46 

lugens 47 

oxylepis 48 

Purshii 49 

Hilaria  rigida 2 

Lycurus  phleoides •. 15 

Muhlenbergia  Buckleyana : 12 

depauperata 14 

Neo  Mexicana 18 

Schaffneri 14 

Munroa  squarrosa 81 

Oryzopsis  fimbriata 11 

membranacea 10 

Paspalum  distii-luim 3 

li viduin 4 

pubiflorum   5 

Plialaris  intermedia  var.  augusta 6 

Pappnphonim  apertum 17 

Wrightii 28 

Schedonnardus  Texanus 24 

Soleropogon  Kar\vinskianus 30 

Sponibi  >lns  argutus 16 

Hurkleyi 17 

interruptus 18 

tricholepis 19 

Wrightii 20 

Stipa  peunata 8 

Sc-ribneri 19 

Trichloris  pluriflora 24 

verticillata 25 

Trie nlia  acuminata 32 

albescens , 33 

eragrostoides 34 

grandiflora 35 

Nealleyi : 36 

pulchella 37 

stricta 38 

Texana 39 

trinerviglumis 40 

Trisetum  Hallii 91 

interruptum 22 

7 


GRASSES  OF  THE  SOUTHWEST. 


II. 


No.  1. 
ELIONLTRUS  TRIPS ACOIDES   H.  B.  K.     (E.  ciliaris  H,  B.  K.) 

Plant  perennial,  with  short  rootstock,  smooth  throughout  or  with  slight  pubes- 
cence near  the  ligule. 

Culms,  loosely  tufted,  erect,  branching,  solid,  terete,  glabrous  and  shiny,  2  to 
4  feet  tall. 

Leaves;  radical  few,  the  broad  loose  sheaths  tapering  into  the  long  involute 
blades  with  scarcely  a  contraction  at  the  ligule;  of  culm  6  to  12;  sheaths  rather 
loose,  open  above,  lower  ones  exceeding  internodes,  upper  ones  shorter;  blades  in- 
volute, slender,  4  to  12  inches  long;  ligule  membranaceous,  ciliate,  truncate,  i  line 
long  or  less. 

Inflorescence  consisting  of  a  terminal,  and  several  distant,  long-peduncled, 
lateral  spikes.  Spikes  linear,  3  to  4  inches  long,  cylindrical;  two  appressed,  1- 
flowered  spikelets  at  each  node  of  the  hairy  rachis,  one  sessile  and  perfect,  and  one 
staminate  on  a  stout  hairy  pedicel  l£  lines  long. 

Sessile  spikelet  narrowly  lanceolate;  first  glume  lanceolate;  nearly  flat,  bifid 
at  apex,  acute  or  obtusish.  rigid,  herbaceous,  ciliate  on  the  prominent  marginal 
nerves,  5  to  7  other  less  prominent  nerves;  second  glume  lanceolate,  membrana- 
ceous, smooth,  obscurely  3-nerved,  2|  to  3  lines  long;  third  and  fourth  glumes 
lanceolate,  acute,  scarious,  thin,  smooth,  the  third  ciliate,  obscurely  3-nerved,  1-j 
to  2i  lines  long;  palet  small  or  wanting;  pedicellate  spikelet  similar,  but  all  parts 
smaller  and  the  first  glume  always  acute  at  apex;  stamens  3. 

PLATE  I;  A,  two  spikelets,  lower  one  perfect,  upper  one  staininate,  a  to/, 
parts  of  perfect  flower;  a,  first  empty  glume,  extreme  forms,  dorsal  view;  and  &, 
ventral  view;  c,  second  empty  glume;  d,  third  empty  glume;  e,  floral  glume;  /, 
palet.  Capital  letters  A,  E  indicate  corresponding  parts  of  staminate  flower. 

Dr  Havard  states  that  this  grass  constitutes  a  large  portion  of  the  vegetation 
of  the  plains  of  southern  Texas.  It  occurs  in  Mexico,  and  also  in  Florida. 


u 


ELIONURUS   TRIPSACOIDE.S 


Kb.  2. 
HILARIA  RIGIDA  (Tlmrb.)  Scrib.  (PlrurapUs  riaida,  Thurb.) 

Plant  perennial,  rigid,  woody  throughout,  except  the  young  growth,  with 
hard  creeping  rootstock  sending  up  scaly  branches. 

Culms  spreading  or  ascending,  branching  freely,  solid,  1  to  2  feet  tall,  woolly 
below. 

Leaves  of  rootstock  appressed,  scarious  scales;  of  culm  often  2-ranked  and 
rather  crowded;  sheaths  longer  than  internodes,  close,  woolly;  blades  involute, 
pungent,  rigid.  1  to  3  inches  long;  ligule  a  dense  white,  woolly  collar. 

Inflorescence  a  narrow,  white  or  purplish  spike,  2  to  3  inches  long,  formed 
of  obovate  clusters  of  3  sessile  spikelets  at  each  node  of  the  rachis. 

Spikelets;  lateral  ones  in  the  cluster  staminate  and  2-  to  3-flowered,  middle  one 
perfect  and  1-flowered;  empty  glumes  all  about  3  lines  long,  forming  an  involucre 
about  the  cluster;  first  glume  of  staminate  spikelet  oblong,  wider  above,  oblique, 
conspicuously  ciliate,  5-nerved,  1  or  2  of  the  nerves  on  one  side  extended  in  short 
dorsal  awns,  second  glume  obovate,  2-lobed  and  ciliate  above,  5-to  6-nerved,  with 
1  or  2  dorsal  awns;  floral  glumes  oblong  or  wedge-shaped,  nearly  equally  2-lobed 
at  apex  or  merely  obtuse,  ciliate,  3-nerved,  midnerve  slightly  excurrerit,  and  one 
lateral  nerve  rather  obscure,  2  to  2^  lines  long;  palet  oblong,  truncate,  slightly 
scabrous  on  the  two  nerves  above,  2  lines  long;  empty  glumes  of  perfect 
flower  equal,  at  the  back  of  the  cluster,  narrow,  cuneate,  oblique  above,  4  to 
G  awned,  ciliate,  2  to  3  lines  long  including  awns;  floral  glume  oblong,  equally 
2-lobed,  ciliate,  2  to  3  lines  long,  3-nerved,  lateral  nerves  equal  and  slightly  excur- 
rent,  midnerve  excurrent  in  an  awn  ^  to  1  line  long;  palet  lance-oblong,  obtuse, 
ciliate  or  lacerate  at  apex,  2-nerved,  2  to  3  lines  long;  stigmas  2,  long,  plumose. 

Grains;  no  mature  grains  found. 

PLA.TE  II;  a  to  d.  parts  of  staminate  flower:  a.  first  empty  glume;  6.  second 
empty  glume;  c,  floral  glume;  d.  palet;  e,  perfect  flower  with  its  two  empty 
glumes;  /to  h,  parts  of  perfect  flower;  /.  floral  glume;  g.  palet;  h,  empty  glume. 

New  Mexico  and  Arizona;  almost  the  only  grass  on  the  driest  desert  land; 
commonly  called  Gayetta  grass.  It  is  considered  a  valuable  grass. 


HILARIA,  RIGIDA 


PASPALUM    DJSTICHUM    Linn. 

Plant  perennial,  the  long  creeping  rootstocks  rooting  at  the  nodes  and  forming 
a  rather  close  sod,  nearly  glabrous  or  sometimes  pubescent,  somewhat  glaucous. 

Culms  one  or  two  in  a  place  ascending  from  the  nodes  of  the  rootstocks, 
branching,  solid,  angular  below,  1  to  2  feet  tall. 

Leaves  variable;  of  rootstocks  mostly  broad,  loose,  membranaceous  scales;  of 
culms  5  to  ?';  sheaths  rather  loose,  closed,  rarely  compressed  and  open,  striate; 
blades  flat  or  slightly  involute,  2  to  2$  lines  wide,  2  to  G  inches  long;  ligule  an 
inconspicuous  tawny,  lacerate  fringe,  decurrent. 

Inflorescence  of  2  rarely  3,  narrow,  erect,  approximate  spikes,  1  to  2i  inches 
long,  the  lower  one  raised  on  a  short  internode  of  the  axis;  rachis  flat,  bearing  the 
two  crowded  rows  of  sessile  spikelets  in  alternate  ranks. 

Spikelets  broadly  oblong-lanceolate,  flattened,  1-flowered,  1  to  li  lines  long; 
first  and  second  glumes  equal,  broadly  lanceolate,  3-nerved  or  unsymmetrically 
4-nerved;  first  acute,  1  line  long,  smooth;  second  with  short,  loose  pubescence; 
floral  glume  broadly  lanceolate,  smooth,  indurated,  3-nerved.  1  line  long:  palet 
indurated,  ovoid,  inclosing  grain,  acute,  obscurely  1-nerved,  1  line  long  and  quite 
as  broad. 

Grain  elliptical-lanceolate,  flattened,  nearly  black  at  maturity,  minutely 
roughened,  1  line  long;  falling  with  the  enveloping  palet  and  glume.  Stigmas  2, 
purple,  prominent. 

PLATE  III;  a,  first  empty  glume,  dorsal  view;  b,  second  empty  gmme;  c, 
flowering  glume,  inside  view;  d,  palet  and  stamens;  e,  pistil. 

Common  in  the  Southern  States,  Texas,  and  westward  to  California.  Near  the 
Gulf,  and  in  moist  ground  it  forms  valuable  pasturage. 


No.  4. 
PASPALUM     LIVIDUM    Trin. 

Plant  perennial,  coarse,  somewhat  tufted  on  a  short  rootstock. 

Culms  few  in  a  place,  erect,  or  decumbent,  geniculate  below,  solid,  terete,  2  to 
3  feet  tall. 

Leaves;  radical  mostly  scarious;  of  culm  0  to  !>;  sheaths  equaling  or  exceeding 
iiiternode,  loose,  often  compressed  and  open,  lower  ones  often  pubescent;  blades 
flat,  hispid  above  and  below  toward  the  tip,  o  lines  wide,  'i  to  0  inches  long;  ligule 
a  tawny,  lacerate,  inembranaceous  fringe,  }  line  long,  decurrent. 

Inflorescence  a  racemose  panicle  of  4  to  8  approximate  spikes,  alternate  on  the 
flattened  axis,  2  to  4  inches  long;  spikes  unilateral,  sessile,  1  to  l£  inches  long; 
rachis  flat  and  smooth,  \  line  wide,  usually  purplish. 

Spikelets  crowded,  usually  in  4  rows,  sessile  or  OH  short  pedicels,  oblanceolate, 
flattish,  1-flowered,  1  to  1^  lines  long;  first  glume  broadly  ovate,  acute,  slightly 
convex,  slightly  roughened  on  back.  :>-nerved.  lateral  nerves  marginal  and  joining 
midnerve  at  apex,  1  line  long;  second  glume  same  but  flat  and  slightly  smaller; 
floral  glume,  indurated,  round  on  back,  with  inrolled  margins,  very  obscurely 
.'5-nerved,  f  line  long;  palet  broadly  oval,  indurated,  nearly  flat,  with  irregular, 
hyaline  margins  below  enfolding  the  seed,  obscurely  2-nerved,  nearly  1  line  long. 

Grain;  a  careful  search  through  is  specimens  produced  but  one  perfect  grain 
and  that  immature,  but  old  enough  to  show  the  form,  obovate,  rounded,  flattened 
on  both  sides  f  line  long. 

PLATE  IV;  a.  first  empty  glume;  b,  second  empty  glume;  c,  floral  glume, 
stamens,  ami  pistil;  //,  palrt,  ventral  view,  with  two  inembranaceous lobos turned  out. 

Found  in  southwestern  Texas;  common  in  Mexico. 


T.Eo2m,de(.. 


No.  5. 
PASPALUM    PUBIFLORUM   Rupt. 

Plant  perennial,  coarse,  rather  glaucous. 

Rootstock  creeping,  branching,  and  often  rooting  at  the  nodes. 

Culms  few  in  a  place,  sometimes  loosely  tufted,  ascending  or  nearly  erect; 
geniculate  below,  branching,  solid,  angular  below,  nearly  terete  above,  smooth, 
18  to  30  inches  tall,  the  lower  joints  woolly. 

Leaves  of  rootstocks  rather  coarse,  loose  scales;  of  culms  3  to  7;  sheaths  shorter 
than  internodes,  loose,  smooth,  often  with  a  few  scattered  hairs  along  the  upper 
margin;  blade  flat,  8-  to  10-nerved,  sparsely  ciliate,  3  to  5  lines  wide,  4  to  8  inches 
long;  ligule  membranaceous,  ovate,  lacerate,  l£  lines  long,  decurrent. 

Inflorescence  3  to- 6  narrow,  spreading  spikes,  alternate  along  the  angular  axis, 
2  to  3  inches  long;  rachis  flat,  bearing  2,  often  4,  rows  of  crowded  spikelets  in  alter- 
nate rows. 

Spikelets  broadly  oblong  or  ovate,  1-flowered,  1  to  l\  lines  long;  first  glume 
broadly  oval  or  hemispherical,  with  infolded  margins,  usually  softly-pubescent, 
3-nerved,  li  to  l£  lines  long;  second  glume  broadly  oval,  flat,  with  infolded  mar- 
gins, nearly  smooth,  3-nerved,  of  the  same  length;  floral  glume  indurate,  ovate- 
oblong,  convex,  with  infolded  margins,  smooth,  obscurely  3-nerved,  1  line  long; 
palet  indurated,  broadly  ovate,  flat,  with  infolded  margins,  smooth,  obscurely 
2-nerved,  1  line  long. 

Grain  oblanceolate,  thick,  flat  on  one  side,  shiny,  dark-brown  at  maturity,  not 
translucent,  1  line  long,  falling  free  or  with  indurated  enveloping  palet. 

PLATE  V;  a.  spikelet,  side  view;  b,  first  empty  glume;  c,  second  empty  glume; 
d,  floral  glume;  e,  palet  and  stamens;  /,  pistil. 

Common  in  Texas  and  extending  to  southern  California.  In  the  Southern 
States  is  a  form  with  smooth  spikelets.  Probably  a  valuable  pasture  grass. 


No.  6. 

PHALARIS     INTERMEDIA    Bosc.    var.    ANGUSTA   Chap.    (P.  an- 

gusta  Nees.). 

Plant  perennial,  rather  coarse,  usually  glaucous  throughout. 

Culms  somewhat  tufted,  erect,  sometimes  branching  below,  terete,  smooth,  or 
scabrous  above,  2  to  4  feet  tall. 

Leaves;  radical,  few,  2  to  4  inches  long,  scarious  in  mature  specimens;  of  culm 
4  or  5;  sheaths  usually  shorter  than  internodes,  rather  loose,  close,  smooth,  blades 
flat,  taper-pointed,  scabrous  on  both  sides,  3  to  5  lines  wide,  3  to  6  inches  long; 
ligule  prominent,  membranaceous,  obtuse,  lacerate  in  age,  2  to  3  lines  long. 

Inflorescence  a  dense,  cylindrical  spike  £  inch  in  diameter,  2  to  4  inches  long; 
the  shortly-pedicellate  spikelets  crowded  on  short,  much  divided,  appressed 
branches. 

Spikelets  with  one  perfect  flower,  and  two  opposite,  small  rudimentary  scales 
or  glumes  below  the  perfect  flower  and  closely  appressed  against  it,  1^  to  2  lines 
long;  first  and  second  glumes  nearly  equal,  lanceolate,  acute,  carinate,  slightly 
winged  on  kee].  above,  herbaceous,  hispid  on  keel,  H  to  2  lines  long;  flowering 
glume  coriaceous,  lanceolate,  acute,  rounded,  completely  enveloping  grain,  clothed 
throughout  with  short,  appressed,  brittle  hairs,  nearly  smooth  and  shining  at  ma- 
turity, light-brown,  !-£  lines  long;  palet  narrow,  pubescent,  1  line  long,  1-nerved. 

Grain  oval,  slightly  compressed,  and  with  small  hook  at  apex,  whitish,  f  to  1 
line  long,  inclosed  in  flowering  glume  from  which  it  is  extracted  with  difficulty. 

PLATE  VI;  a,  empty  glumes;  b,  floral  glume;  c,  palet. 

Grows  from  Florida  to  Texas  and  California.  In  Texas  it  has  been  cultivated, 
and  is  a  very  prolific  and  valuable  grass. 


No.  7. 
ARISTIDA    PURPUREA  Nutt. 

Plant  annual  or  short  lived  perennial,  often  purplish  especially  in  the  inflor- 
escence. 

Culms  tufted,  erect,  slender,  not  branching,  nearly  smooth,  1  to  2  feet  tall. 

Leaves;  radical  and  of  radical  shoots  with  narrow,  close  sheaths  and  slender 
involute  blades,  4  to  10  inches  long;  of  culm  3  or  4;  lower  sheaths  longer  than  inter- 
nodes,  upper  ones  much  shorter,  close,  smooth  ;  blade  involute,  hispid  above,  3  to 
6  inches  long  ;  ligule  a  line  of  fine  short  hairs,  somewhat  hairy  at  the  sides. 

Inflorescence  rather  loose,  narrow,  erect  or  slightly  nodding  panicle,  4  to  G 
inches  long;  branches  2  or  3  at  each  node,  unequal,  the  lower  1  to  2  inches  long, 
naked  below,  each  bearing  2  to  5  pedicellate  or  nearly  sessile  spikelets. 

Spikelets  narrow,  1-flowered,  5  to  6  lines  long;  first  glume  narrowly  lance-lin- 
ear, emarginate,  mucronate,  rounded,  hispid  on-  keel,  1-nerved,  4  to  4^  lines  long; 
second  glume  same  but  nearly  2  lines  longer;  stipe  hairy,  |  line  long;  floral  glume 
linear-lanceolate,  rounded,  slightly  hispid  on  the  nerve  above,  4  lines  long,  termi- 
nating in  3  separate,  slender,  minutely  hispid  awns  1  to  2  inches  long;  palet  obo- 
vate,  thin,  i  to  f  line  long. 

PLATE  VII:  a,  spikelet  twice  as  large  as  natural  size. 

Abundant  on  plains  and  ridges,  in  several  varieties,  from  Texas  to  British 
America.  It  is  the  earliest  available  grass  for  cattle  in  the  spring,  but  of  little 
value  when  mature. 


No.  8. 
STIPA    PEN  NAT  A   Linn.  var.  Neo  Mexicana  Thurb. 

Plant  perennial  with  strong  coarse  roots. 

Culms  erect,  densely  tufted,  not  branching,  hollow,  smooth,  1  to  3  feet  tall. 

Leaves  of  radical  shoots  numerous,  with  round,  close,  smooth  sheaths,  and 
narrow  closely  involute  blades,  10  to  12  inches  long;  of  culm  3  to  4,  sheaths  smooth, 
usually  exceeding  internodes;  blades  like  those  of  radical  shoots  but  shorter;  lig- 
ules  membranaceous,  rounded,  and  ciliate  above,  less  than  i  line  long. 

Inflorescence  a  narrow  racemose  panicle  4  to  5  inches  long;  branches  almost 
appressed,  the  lower  2  to  3  inches  long,  each  bearing  1  to  3  pedicellate  spikelets. 

Spikelets  1-flowered;  first  and  second  glumes  nearly  equal,  lanceolate,  long; 
awn-pointed,  herbaceous,  5  to  7-nerved,  l£  to  H  inches  long;  floral  glume  terete, 
coriaceous,  yellow,  clothed  throughout  with  close  appressed  pubescence,  5  to  7  lines 
long,  contracted  at  the  apex,  terminating  in  a  twisted,  bent  awn,  feathered  above, 
4  to  6  inches  long;  palet  narrowly  terete,  hard,  smooth,  5  to  6  lines  long. 

Grain  narrow,  reddish,  2  to  3  lines  long. 

PLATE  VIII;  a,  spikelet  dissected,  about  natural  size. 
Texas,  New  Mexico,  and  Arizona. 


No.  0. 
STIPA  SCRIBNERI  Vasey. 

Rootstock  short,  horizontal,  with  coarse  fibrous  roots. 

Culms  tufted,  erect,  terete,  smooth,  l£  to  2%  feet  tall,  unbranched. 

Leaves;  from  base  half  as  long  as  the  culm;  of  stem  3  or  4;  sheaths  smooth, 
or  lower  ones  slightly  scabrous,  nearly  equaling  or  slightly  exceeding  the  inter- 
nodes,  close;  blade  flat  below,  involute  above  toward  the  long  tapering  point,  mid- 
nerve  inconspicuous,  1  to  2  lines  wide,  4  to  10  inches  long;  ligule  truncate,  1  line 
long. 

Inflorescence  an  erect  slender  panicle,  its  base  inclosed  by  the  upper  sheath, 
narrow  and  close,  5  to  8  inches  long;  rachis  slightly  angular,  not  flexuous;  branches 
in  twos  or  threes,  appressed,  1  to  2  inches  long,  each  bearing  2  to  4  spikelets  on 
short  pedicels. 

Spikelets  1-flowered;  empty  glumes  unequal,  the  first  6  to  7  lines,  and  second 
5  lines  long,  linear-lanceolate,  acuminate,  both  3-nerved,  smooth;  floral  glume 
about  4  lines  long,  white-hairy,  the  hairs  longer  above  forming  a  crown  or  tuft  1 
line  long;  awn  rather  slender,  8  to  9  lines  long,  not  hairy;  stipe  short,  acute;  palet 
less  than  1  line  long,  obtuse,  and  adherent  to  grain. 

Grain  nearly  cylindrical,  yellow,  opaque,  2  to  2£  lines  long. 

PLATE  IX;  a,  spikelet  dissected  and  enlarged. 
Arizona  and  New  Mexico.     Generally  in  strong  tufts. 


WRSr/ioll, 


No.  10. 

ORYZOPS1S  MEMBRANACEA  (Pursh.).    (Stipa  membranacea  Pursh.) 
Eriocoma  cuspidata  Nutt.) 

Plant  perennial,  closely  tufted,  thickened  at  base. 

Culms  slender,  nearly  erect,  not  branching,  geniculate,  solid,  terete,  smooth, 
12  to  18  inches  tall. 

Leaves;  radical,  numerous,  the  scarious  sheaths  clustered  thick  about  the  base 
of  the  culms;  blades  involute,  smooth,  6  to  10  inches  long;  of  the  culms  3;  lower 
sheaths  shorter  than  internodes,  smooth  and  close,  upper  sheath  longer  and  loose; 
blades  like  those  of  radical  leaves;  ligule  membranaceous,  ovate,  acute,  or  lace- 
rate, 1  line  long,  prominently  decurrent. 

Inflorescence  a  very  loose,  erect  or  flexuous  panicle  4  to  6  inches  long,  included 
at  the  base,  usually  with  2  or  3  nearly  equal  axes;  branches  mostly  in  pairs,  dis- 
tant, horizontal,  divided  in  pairs  beyond  the  middle,  bearing  solitary  spikelets  on 
long  flexuous  pedicels. 

Spikelets  1-flowered,  3  lines  long;  first  and  second  glumes  equal,  inflated  and 
widened  below,  narrowed  above  to  a  long  sharp  point,  scarious  except  the  5  rather 
obscure  nerves,  minutely  pubescent  throughout,  3  lines  long;  floral  glume  ovoid 
or  oblong,  hard,  dark-brown,  profusely  clothed  with  long  white  hairs,  1-J  lines 
long,  obscurely  nerved,  terminating  in  an  awn  2  lines  long,  which  falls  at  maturity; 
palet  conical,  smooth,  hard,  brown,  obscurely  nerved,  1|  lines  long. 

Grain  oval,  light-yellow,  f  line  long. 

PLATE  X;  a,  spikelet;  b,  empty  glumes;  c,  floral  glume,  with  hairs  and  awn; 
d,  same  after  hairs  and  awn  have  fallen;  e,  palet.  In  the  floral  glume,  c,  the  awn 
should  be  represented  more  to  one  side. 

Texas  to  California,  northward  to  British  Columbia,  usually  in  sandy  or  grav- 
elly soil.  A  valuable  grass.  The  large  seeds  are  nutritious,  and  cattle  fatten 
where  the  grass  is  abundant. 


T.ff')lm.,olei. 


No.  11. 
ORYZOPSIS  FIMBRIATA  Hemsl.     (Stipa  fimbriata  Kth.) 

Culms  tufted  with  many  root  leaves  at  base,  erect,  striate,  smooth,  slender,  1  to 
2  feet  tall. 

Leaves  of  stem  2  to  4;  lower  sheaths  much  shorter  than  internodes,  closely 
wrapping  the  culm  with  the  niembranaceous  inner  fold;  blade  filiform,  involute, 
^  line  wide,  1  to  3  inches  long,  much  exceeded  by  the  in  volute  setaceous  root  leaves; 
ligule  conspicuous,  obtuse,  wider  than  blade,  1  line  long. 

Inflorescence  a  loose,  erect,  or  spreading  panicle,  4  to  6  inches  long;  rachis  angu- 
lar, slightly  scabrous,  flexuous  towdrd  apex,  branches  in  twos  or  threes,  spreading 
or  lower  ones  even  deflexed,  filiform,  1  to  2  inches  long,  each  bearing  2  to  4  spike- 
lets  on  pedicels  3  to  5  lines  long. 

Spikelets  obovate,  2  to  2$  lines  long;  first  glume  broadly  lanceolate,  upper 
half  scarious  with  acuminate  apex,  often  purplish,  5-nerved,  smooth,  2  to  2%  lines 
long;  second  glume  same  but  slightly  smaller;  floral  glume  coriaceous,  orbicular, 
obscurely  5-nerved,  covered  with  loose  white  hairs  longer  at  base,  and  bearing  a 
smooth  flexuous  awn  5  to  8  lines  long;  palet  obovate,  acuminate,  2-nerved,  1|  lines 
long. 

PLATE  XI;  a,  spikelet  dissected  and  enlarged;  b,  panicle  at  maturity. 
Texas,  New  Mexico,  and  Arizona. 


No.  12. 

MUHLENBERGIA   BUCKLEYANA    Scribn.     (Muhlenbergia  Texana 

Buckl.  not  Thurb.) 

Plant  annual,  diffuse,  spreading. 

Culms  tufted  at  base,  spreading,  terete,  slender,  smooth,  branching  below,  10 
to  15  inches  tall. 

Radical  leaves  few  and  small;  of  culm  1  to  3,  usually  2;  sheaths  rather  loose, 
somewhat  vaginate,  or  compressed  and  open,  slightly  scabrous,  longer  than  inter- 
nodes;  blade  flat  or  involute,  scabrous  on  both  sides,  1  to  2  inches  long. 

Inflorescence  an  oblong,  loose,  spreading  panicle  4  to  8  inches  long:  rachis  and 
branches  slender,  terete,  often  purple,  the  latter  mostly  alternate,  1  to  3  inches  long, 
bearing  solitary  spikelets  on  slender  pedicels  1  to  2  lines  long. 

Spikelets  narrowly  lanceolate,  1 -flowered,  1  line  long;  first  glume  ovate,  acute, 
hyaline,  pubescent,  1-nerved,  £  line  long  with  a  very  short  awn;  second  glume 
same  but  little  larger:  floral  glume  oblong,  2-toothed  at  apex,  i  to  1  line  long, 
3-nerved,  slightly  pubescent  on  the  nerves,  midnerve  excurrent  in  an  awn  as  long 
as  the  glume;  palet  lanceolate,  nearly  acute,  thin,  2-nerved,  |  line  long. 

Grain  narrowly  obovate,  rounded  at  apex,  compressed,  reddish-amber,  ^  line 
long,  falling  with  floral  glume  and  palet  but  easily  escaping. 

PLATE  XII;  a,  spikelet  enlarged;  6,  empty  glumes;  c,  floral  glume;  d,  palet. 
Texas,  New  Mexico  to  Mexico  on  rocky  hills. 


No.  13. 
MUHLENBERGIA    NEO-MEXICANA   Vasey. 

Plant  slender,  tufted,  perennial,  from  thick,  knotted,  or  sometimes  creeping 
rootstocks. 

Culm  branching  freely  below,  erect,  slender,  terete,  nearly  smooth,  12  to  18 
inches  tall. 

Leaves;  of  culms  4  to  6;  sheaths  longer  than  internodes,  close,  slightly  rough- 
ened; blades  erect,  appressed,  closely  involute  and  setaceous,  2  to  3  inches  long; 
ligule  an  irregular,  ovate,  lacerate  membrane  i  line  long. 

Inflorescence  a  narrow,  erect  or  slightly  nodding  panicle,  3  to  4  inches  long, 
often  purple;  branches  alternate,  erect,  hispid,  i  to  1  inch  long,  bearing  rather 
close  clusters  of  spikelets  on  hispid  pedicels  £  to  li  lines  long. 

.  Spikelets  narrow,  1-flowered,  2  lines  long;  empty  glumes  equal,  lance-ovate, 
acute,  carinate,  hyaline,  1-nerved,  1  line  long,  terminating  in  a  slender  awn  i  to  ^ 
line  long;  floral  glume  narrowly  conical,  lanceolate,  acute  when  unrolled,  thin, 
smooth,  minutely  pubescent  at  base,  3-nerved,  terminating  in  an  awn  $  inch  long; 
palet  obscurely  2-nerved,  2  lines  long,  often  projecting  out  of  the  floral  glume; 
stamens  3. 

Grain,  none  present  in  the  24  specimens  examined. 

PLATE  XIII ;  a,  panicle  at  maturity;  b,  cluster  of  spikelets;  c,  spikelet  enlarged. 
Eocky  ledges.  New  Mexico  and  Arizona. 


,  del 


No.  14. 
MUHLENBERGIA   SCHAFFNERI   Fourn. 

Plant  low,  annual  or  short-lived  perennial. 

Culms  tufted,  procumbent  or  spreading,  branching  freely,  2  to  4  inches  tall. 

Leaves;  radical,  few  and  small;  of  culm  3  to  5;  sheaths  compressed,  open, 
striate,  scabrous  011  both  sides,  margins  white,  i  to  1  inch  long;  ligule  membrana- 
ceous,  lacerate,  f  line  long,  decurrent  in  prominent  hyaline  margins  on  the  sheath. 

Inflorescence  a  narrow  contracted  panicle,  1  to  2  inches  long,  often  included  at 
base,  rachis  and  branches  angular,  hispid. 

Spikelets  sessile,  appressed,  narrow,  1|  to  2  lines  long;  first  glume  lanceolate,  the 
apex  lobed,  with  2  short  unequal  or  nearly  equal  teeth  at  apex,  hispid,  2-iierved,  her- 
baceous, rigid,  1  to  li  lines  long;  second  glume  linear-lanceolate,  acute,  carinate, 
short-awned  at  apex,  hispid,  1 -nerved,  1%  to  2i  lines  long,  including  awn;  floral 
glume  ovate,  2  minute  hyaline  teeth  at  apex,  slightly  hispid,  ciliate  below,  3-nerved, 
with  slender  awn  f  to  2  lines  long,  or  sometimes  awnless;  palet  ovate,  acute, 
2-iierved,  thin,  smooth,  1^  to  1^  lines  long. 

Grain  narrowly  cylindrical,  reddish  amber  color,  f  line  long,  falling  with  palet 
and  glume  but  easily  escaping. 

PLATE  XIV,  No.  2,  lower  figure;  a,  first  empty  glume;  6,  second  empty 
glume;  c,  floral  glume;  d,  palet. 

Arizona. 


No.  14. 
MUHLENBERGIA   DEPAUPERATA   Scrib. 

Plant  low,  tufted,  annual  or  short  lived  perennial. 

Culms  spreading,  branching  at  each  node,  3  to  4  inches  tall. 

Leaves;  radical,  few  or  none;  of  culm  2  to  4,  with  loose,  smooth,  broad,  open 
sheaths,  and  short  folded  or  involute  blades;  ligule  membranaceous,  lacerate,  de- 
current. 

Inflorescence  a  narrow,  contracted,  rather  close  panicle,  2  to  3  inches  long, 
usually  included  below,  rachis  and  branches  angular,  hispid,  pedicels  short. 

Spikelets  narrow,  1-flowered,  l£  to  2  lines  long;  first  glume  ovate,  obliquely 
2-toothed  at  apex,  scarious,  minutely  hispid,  obscurely  1-nerved,  f  to  1  line  long; 
second  glume  lanceolate,  narrowing  at  apex  to  a  slender,  awn-like  point,  scarious, 
minutely  hispid,  1  to  li  lines  long;  floral  glume  narrowly  lanceolate,  with  2  minute 
teeth  at  apex,  rounded  011  back,  hispid.  3-nerved,  1-j  to  2  lines  long,  midnerve 
excurrent  in  an  awn  2  to  5  lines  long;  palet  lanceolate,  acuminate,  rounded,  envel- 
oping grain,  minutely  pubescent,  2-nerved,  1^  to  If  lines  long. 

Grain  narrowly  cylindrical,  reddish-amber,  lighter  above,  1  line  long,  falling 
with  palet  and  glume  but  easily  escaping. 

PLATE  XIV,  No.  1,  upper  figure;  a,  spikelet  enlarged;  6,  empty  glumes;  c, 
floral  glume;  d,  palet. 

Very  close  to  M.  Schaffneri  and  perhaps  but  a  variety  of  it, 

Arizona, 


d  c 


No.  15. 
LYCURUS   PHLEOIDES  H.  B.  K. 

Plant  perennial  from  thickened,  slightly  bulbous  base. 

Culms  tufted,  erect  or  ascending,  rather  weak,  branching,  solid,  nearly  terete, 
smooth,  1  to  2  feet  tall. 

Leaves;  radical  numerous,  with  short,  close  sheaths  and  flat,  folded  or  invo- 
lute blades  1  to  2  inches  long,  with  white  margins  and  midrib;  of  culm  4  or  5; 
sheaths  much  shorter  than  internodes,  loose  and  open,  smooth;  blades  like  those 
of  radical  leaves  but  longer;  ligule  membranaceous,  ovate,  acute,  oblique,  decur- 
rent  on  one  side,  1  line  long. 

Inflorescence  a  dense,  cylindrical  spike  i  inch  in  diameter,  2  to  3  inches  long. 

Spikelets  1  to  3  on  each  of  the  short  branches  of  the  rachis,  one  or  two  of 
which  are  commonly  imperfect;  first  glume  oblong,  thin,  2-nerved,  |  to  f  line  long, 
terminating  in  2  or  (rarely)  3,  unequal,  hispid  awns,  1  to  3  lines  long;  second  glume 
ovate,  acute,  carinate,  membranaceous,  1-nerved,  f  to  1  line  long,  terminating  in 
an  awn  2  to  3  lines  long;  floral  glume  lanceolate-oblong,  acute,  pubescent  through- 
out, thicker  than  the  empty  glumes,  3-nerved,  If  to  2  lines  long,  terminating  in  a 
hispid  awn  l£  to  2  lines  long;  palet  lanceolate,  2-toothed  at  apex,  rounded,  2-nerved, 
thinly  pubescent,  l£  lines  long;  the  flowers  are  subject  to  the  attack  of  an  insect, 
which  renders  the  palet  inflated  and  hardened  below. 

Grain  narrowly  lanceolate  or  linear,  yellow,  £  line  long. 

PLATE  XV;  A,  perfect  spikelet,  with  abortive  spikelet  below;  a,  spikelet  with 
the  palet  distorted;  b,  first  empty  glume;  c,  second  empty  glume;  d,  floral  glume, 
ventral  view;  e,  palet;  /,  palet  of  pistillate  flower  distorted  by  an  insect. 

Texas  and  Mexico,  northward  to  Colorado. 


THolm.,d<sl, 


No.  16. 

SPOROBOLUS    ARGUTUS  Kth.    ( Vilfa  Arkansana  Trin.     Vilfa  arguta 

Nees.) 

Plant  annual,  smooth  throughout  except  the  scabrous  margins  of  the  leaves. 

Culm  tufted,  spreading,  weak,  branching  below,  smooth,  6  to  12  inches  tall. 

Leaves  of  radical  shoots  numerous,  with  mostly  smooth,  loose,  scarious  sheaths 
and  flat  blades  2  to  3  inches  long;  of  culm  2  or  3,  lower  sheaths  mostly  shorter 
than  internodes,  close;  blades  like  those  of  radical  shoots,  but  upper  ones  much 
shorter;  ligule  a  line  of  short  tawny  bristles. 

Inflorescence  a  rather  narrow  or  sometimes  spreading,  erect  panicle,  2  to  3 
inches  long,  often  included  at  base;  branches  3  to  5  at  base,  alternate  above,  divided 
and  bearing  many  pedicellate  spikelets  on  the  outer  two-thirds. 

Spikelets  oblong-ovate,  1-flowered,  f  line  long;  first  glume  oblong,  obtusish, 
thin,  hyaline,  smooth,  1 -nerved,  f  line  long;  floral  glume  lance-ovate,  acute,  thin, 
1-nerved,  f  line  long;  palet  broadly  ovate,  thin,  obscurely  2-nerved,  f  line  long. 

Grain  elliptical,  compressed,  light-brown,  with  reddish  scar,  utricular,  falling 
free. 

PLATE  XVI;  «,  empty  glumes  enlarged;  6,  floral  glume  and  palet  inclosing 
grain. 

Texas  to  Arizona  and  Mexico. 


No.  17. 
SPOROBOLUS    BUCKLEYI  Vasey. 

Culms  erect,  loosely  tufted,  slender,  not  branching,  compressed,  especially 
below,  smooth,  2  to  3  feet  tall. 

Leaves;  radical,  few,  sheaths  green  or  purplish,  compressed,  tapering  into 
slender,  mostly  folded,  smooth,  long  pointed  blades,  6  to  15  inches  long,  green  at 
maturity;  of  culm  4  or  5;  sheaths  mostly  exceeding  internodes,  lower  ones  com- 
pressed and  open,  upper  close,  blades  like  those  of  radical  leaves;  ligule  a  minute 
tawny  fringe. 

Inflorescence  a  loose,  spreading,  erect  panicle,  10  to  15  inches  long;  branches 
spreading  or  becoming  reflexed,  mostly  alternate,  3  to  5  inches  long,  slender,  bear- 
ing beyond  the  lower  third,  short  branches  of  pedicellate  spikelets. 

Spikelets  obovate,  1-flowered,  f  line  long;  first  glume  lanceolate,  acute,  thin, 
smooth,  1-nerved,  £line  long;  second  glume  same,  but  nearly  twice  as  large;  floral 
glume  ovate,  acuminate,  hyaline,  smooth,  1-nerved,  f  line  long;  palet  lance-ovate, 
acute,  obscurely  2-keeled,  ^  line  long,  in  age  splitting  to  the  base. 

Grain  elliptical-globose,  utricle  light-brown,  £  line  long. 

PLATE  XVII;  a,  spikelet  enlarged. 

Well  distinguished  by  the  large  panicle  of  capillary  branches  and  many 
flowered,  small  spikelets.  A  handsome  species. 

Texas  to  Mexico. 


No.  18. 

SPOROBOLUS    INTER RUPTUS   Vasey.     (Vilfa   interrupt  Vasey   in 
Special  Report  No.  63,  Department  of  Agriculture,  1883.) 

Plant  perennial,  with  densely  tufted,  bulbous  base. 

Culms  erect,  not  branching,  smooth,  terete,  1  to  2  feet  tall. 

Leaves;  radical  and  from  radical  shoots,  numerous,  with  scarious,  often  red- 
dish, glabrous  or  pubescent,  tapering  sheaths,  and  mostly  flat,  smooth  or  loosely 
pubescent  erect  blades,  3  to  5  inches  long;  of  culm  2  or  3;  sheaths  longer  than  in- 
ternodes,  close,  open  above,  smooth  blades,  mostly  involute,  erect,  1  line  wide,  1 
to  3  inches  long;  ligule  a  narrow  ciliate  fringe. 

Inflorescence  a  narrow,  open  or  interrupted,  erect  panicle,  4  to  6  inches  long; 
rachis  flexuous,  branches  alternate  or  verticillate  below,  in  twos  or  threes  above, 
1  to  2  inches  long. 

Spikelets  short-pedicellate,  narrow,  1-  or  2-flowered,  2  to  3  lines  long;  first 
glume  lanceolate,  acute,  carinate,  scarious,  smooth,  1-nerved,  1  to  i±  lines  long; 
second  glume  ovate-lanceolate,  nearly  twice  as  large;  floral  glume  ovate-lanceo- 
late, acute,  membranaceous,  smooth,  1-nerved  or  obscurely  3-nerved  above.  2  to  3 
lines  long;  palet  broadly  lanceolate,  bifid  at  apex,  thin,  hyaline,  smooth,  slightly 
2- keeled,  2  lines  long;  anthers  3,  long,  reddish  purple;  stigmas  2,  greenish, 
'plumose. 

Grain,  no  mature  grains  seen. 

PLATE  XVIII;  a,  spikelet  enlarged;  6,  empty  glumes;  c,  floral  glume;  d, 
palet;  2,  typical  panicle. 

Arizona. 


•BULUS    INTEF.RU1 


No.  19. 
SPOROBOLUS  TRICHOLEPIS  (Torr).    ( Vilfa  tricholepis  Torr. ) 

Plant  slender,  perennial,  often  purplish  in  culm  and  inflorescence,  smooth 
throughout. 

Culms  tufted,  erect,  seldom  branching,  smooth,  slightly  compressed,  1  to  -2 
feet  tall. 

Leaves  of  radical  shoots  with  rather  loose,  scarious  sheaths  and  narrow  invo- 
lute blades  2  to  4  inches  long;  of  culm  2  or  3;  sheaths  close,  nearly  equaling -or 
exceeding  internodes,  blades  involute,  erect,  2  to  3  inches  long;  ligule  membrana- 
ceous,  truncate,  lacerate,  decurrent,  i  line  long  or  less. 

Inflorescence  an  ovate,  pyramidal,  erect,  or  flexuous  panicle,  4  to  6  inches  long; 
branches  mostly  alternate,  slightly  spreading,  1  to  2  inches  long,  divided  and 
rather  loosely  flowered  on  the  upper  two-thirds. 

Spikelets  on  long  slender  pedicels,  lanceolate,  1-flowered,  l£  lines  long;  first 
and  second  glumes  nearly  equal  lanceolate,  acute  or  obtuse,  carinate,  thin,  smooth, 
1-nerved,  1  to  li  lines  long;  floral  glume  lanceolate,  acute,  or  obtuse,  mem- 
branaceous,  pubescent  or  villous  on  the  3  nerves,  H  lines  long;  palet  lanceolate, 
acute,  membranaceous,  slightly  ciliate  above,  pubescent  on  the  2  approximate 
nerves,  or  nearly  smooth,  l£  lines  long. 

Grain  narrowly  elliptical,  compressed,  yellow,  ^  line  long. 

PLATE  XIX;  a,  empty  glumes;  b,  floral  glume  and  palet  opened  to  show 
stamens  and  pistil. 

Mexico  northward  to  Colorado. 


D.Glszewskt.dLel 


No.  20. 
SPOROBOLUS    WRIGHTII  Munro  in  Herb. 

Plant  perennial,  coarse,  with  thickened  bulbous  base. 

Culms  erect,  not  branching,  terete,  smooth  and  shining,  2  to  4  feet  tall. 

Leaves;  radical,  few,  scarious  sheaths  at  maturity;  of  culm  4  or  5;  sheaths 
mostly  exceeding  internodes,  closed,  slightly  hairy  at  the  throat;  blades  flat  or 
involute,  2  or  3  lines  wide,  1  to  2  feet  long;  ligule  a  minute  fringe. 

Inflorescence  a  slender,  erect,  lanceolate  panicle,  10  to  13  inches  long;  branches 
mostly  alternate,  slender,  erect-spreading,  1  to  4  inches  long,  bearing  many  shortly- 
pedicellate  spikelets  on  the  outer  two-thirds. 

Spikelets  lanceolate,  1-flowered,  1  line  long;  first  glume  ovate,  barely  acute, 
membranaceous,  1-nerved,  i  to  i  line  long;  second  glume  same,  but  twice  as  large; 
floral  glume  broadly  lanceolate,  acute,  membranaceous,  smooth,  1-nerved,  f  line 
long;  palet  lanceolate,  cleft  at  apex,  slightly  2-keeled,  f  line  long. 

Grain  elliptical,  compressed,  brown,  £  line  long. 

PLATE  XX;  a,  spikelet  enlarged. 

A  tall  coarse  grass,  growing  in  dense  tufts,  commonly  called  Saccaton  or  Zac- 
ate.  Probably  too  coarse  to  be  of  agricultural  value. 

Western  Texas  to  southern  California, 


No.  21. 
TRISETUM    HALLII  Scrib. 

Plant  annual. 

Culms  slender,  not  branching,  geniculate,  ascending,  scabrous,  1  to  1$  feet 
tall. 

Leaves;  radical,  few  and  small;  of  culm  3  or  4;  sheaths  usually  exceeding 
internodes,  open  above,  somewhat  scabrous:  blades  flat  or  slightly  involute,  taper- 
pointed,  scabrous  on  both  sides,  1  to  1^  lines  wide,  3  to  5  inches  long;  ligule  mem- 
branaceous,  truncate,  lacerate,  1  line  long. 

Inflorescence  a  rather  narrow,  contracted,  close,  erect,  or  flexuous  panicle,  4  to 
6  inches  long,  incl uded  or  but  slightly  exserted;  branches  mostly  in  threes,  slightly 
spreading,  i  to  1  inch  long,  bearing  pedicellate  spikelets;  crowded  along  their 
entire  length. 

Spikelets  obovate,  3-  to  4-flowered,  upper  one  sterile,  small  and  abortive,  2  to 
2i  lines  long;  first  glume  narrowly  lanceolate,  acute,  herbaceous,  hispid  on  keel, 
3-nerved,  -J  line  wide,  2  lines  long;  second  glume  oblong-lanceolate,  5-nerved,  twice 
as  wide  as  the  first;  internode  of  rachilla  slender,  curved,  articulate  above,  smooth, 
\  line  long;  floral  glume  lanceolate,  with  two  attenuate  teeth  at  apex,  scarious, 
scabrid,  1^  to  2  lines  long,  obscurely  3-nerved,  mid-nerve  excurrent  in  a  slender 
awn  2  to  4  lines  long;  palet  narrowly  linear,  lanceolate  when  spread  out,  thin, 
2-keeled,  1  line  long,  not  inclosed  in  floral  glume. 

Grains,  none  found  in  the  specimens  examined 

PLATE  XXI;  a,  spikelet;  b,  empty  glumes;  c,  floral  glume;  d,  palet. 

This  differs  from  T.  interruptum  Buckl.  in  its  heavier  panicle,  shorter  teeth  of 
the  flowering  glume,  and  the  higher  insertion  of  the  awn.  Both  species  occur  in 
Texas, 


No.  22. 
TRISETUM  INTERRUPTUM    Buckley. 

Plant  slender,  tufted,  annual,  rather  glaucous  throughout. 

Roots  numerous,  fine. 

Culms  ascending,  geniculate,  branching,  terete,  smooth,  G  to  18  inches  tall. 

Leaiies  of  radical  shoots  numerous,  with  smooth  or  cinerous-pubescent  sheaths 
and  flat  blades,  hispid  above,  2  to  3  inches  long;  of  culm  3  to  5;  sheaths  usually 
little  shorter  than  internodes,  smooth  or  somewhat  scabrous  or  pubescent;  blades 
flat  or  involute,  scabrous,  2  to  3  inches  long;  ligule  inernbranaceous,  lacerate, 
obliquely  truncate,  1  line  long. 

Inflorescence  a  narrow,  somewhat  interrupted,  erect  or  flexuous  panicle,  3  to 
5  inches  long;  branches  in  2's  or  3's  of  unequal  length,  i  to  1  inch  long. 

Spikelets  sessile,  obovate,  3-  to  4-flowered,  upper  one  sterile  or  small  and  abor- 
tive, 2  to  2%  lines  long;  first  glume  oblanceolate,  acute,  herbaceous,  hispid  on 
keel,  3-nerved,  1£  to  2  lines  long;  second  glume  same,  but  twice  as  wide  and 
5-nerved;  internode  of  rachilla  curved,  glabrous,  |  line  long;  floral  glume  lanceo- 
late, rounded  on  back,  scarious  above,  rigid,  smooth,  about  2  lines  long,  3-nerved, 
ending  in  2  slender  teeth,  2  lateral  nerves  uniting  above  with  the  midnerve  and 
forming  above  the  middle  a  slender  hispid  awn,  2  to  3  lines  long;  palet  narrowly 
linear,  wider  at  top,  lanceolate  when  spread  out,  thin,  smooth,  2-keeled,  cleft  at 
apex,  standing  out  of  floral  glume,  1  line  long. 

Grain  yellowish,  opaque,  elliptical,  flattened,  1  line  long. 

PLATE  XXII;  a,  floral  glume,  side  view;  &,  palet;  c,  spikelet;  d  (marked  a  in 
plate),  empty  glumes.  The  floral  glume,  a?  is  not  well  figured, 

Abundant  in  Texas, 


TRISETUM    INTERRUPTUM, 


No.  23. 

CHLORIS   SWARTZIANA  Doll.    (Chloris  petrcea   Swz.  non.     Thunb.) 
(Schultesia  petrcea  Spreng.)     (?  Eustachys  petrcea  Desv.) 

Plant  perennial,  from  short  rootstock,  light  green  or  more  or  less  purplish 
throughout. 

Culm  erect,  or  genticulate  and  spreading  below,  frequently  branched,  flatly 
compressed,  smooth,  1  to  2  feet  tall. 

Leaves;  radical,  with  closely  compressed,  smooth,  equitant,  divergent  sheaths, 
and  flat  or  folded  blades,  round-pointed,  scabrous  on  the  edge,  2  lines  wide,  4  to 
10  inches  long;  of  stem  3  to  5,  sometimes  opposite;  sheaths  compressed,  loose, 
smooth,  shorter  than  internodes;  lower  blades  like  those  of  radical  leaves  but 
shorter,  and  upper  ones  reduced  to  nearly  none;  ligule  a  minute,  ciliate,  membraiia- 
ceous  fringe. 

Inflorescence  a  digitate  cluster  of  3  to  6  sessile,  linear,  erect,  slightly  spreading 
spikes,  2  to  3  inches  long,  bearing  the  crowded  sessile  spikelets  in  two  rows  on  one 
side  of  the  slender,  scabrid  rachis. 

Spikelets  2-flowered,  upper  flower  sterile;  first  glume  broadly  ovate-acute, 
smooth,  1-nerved,  scarious,  ^  line  long;  second  glume  obovate,  2  minutely  toothed 
lobes  at  apex  and  a  short  hispid  awn  formed  by  the  excurrent  nerve,  hispid  on  back, 
f  to  1  line  long;  floral  glume,  rotund,  broadly  acute,  or  rounded  and  mucronate, 
coriaceous,  brown,  ciliate,  pubescent  on  the  lower  two-thirds  of  the  single  nerve, 
smooth  above;  palet  ovate-lanceolate,  convex,  obscurely  2-nerved,  1  line  long;  ster- 
ile flower  a  broadly  ovate,  truncate  glume,  folded  triangular,  brown,  -^  line  long. 

Grain  translucent,  creamy-white,  triangular,  ^  line  long,  falling  with  spikelet 
intact  except  the  empty  glumes  which  are  left  on  the  rachis. 

PLATE  XXIII;  a,  spikelet;  b,  floral  glume,  sterile  flower,  stamens  and  stigmas; 
c,  second  empty  glume;  d,  first  empty  glume;  palet  not  shown. 

Low  grounds  near  the  Gulf,  from  Florida  westward  to  Texas. 


T.Xolrn.  c 


CHLORIS  Doll 


No.  24. 
TRICHLORIS  PLURFLORA  Fourn. 

Plant  rather  coarse,  somewhat  glaucous  throughout  or  purplish  in  the  inflor- 
escence. 

Culms  few,  from  loosely  tufted,  slightly  bulbous  base,  erect,  solid,  terete, 
smooth,  rarely  branching,  2  to  3  feet  tall. 

Leaves;  radical  and  from  sterile  culms,  numerous,  with  loose  sheaths,  and  flat, 
taper-pointed  blades,  3  to  4  lines  wide  and  8  to  10  inches  long,  scabrous  above  and 
below,  with  scattered  hairs,  near  the  ligule;  of  stem  5  to  7;  sheath  equaling  or 
exceeding  interuode,  loose  and  open  above,  smooth;  blade  like  that  of  the  radical 
leaves;  ligule  a  row  of  rusty,  fine  hairs  i  line  long. 

Inflorescence  an  obovate  panicle  of  10  to  15  slightly  spreading,  narrow,  sessile 
approximate  spikes,  scattered  one  or  two  in  a  place  along  the  short  rachis.  Spikes 
unilateral,  rachis  hispid,  2  to  4  inches  long. 

Spikelets  nearly  sessile,  with  3  or  4  flowers,  the  upper  ones  sterile;  first  glume 
narrowly-lanceolate,  terminating  in  an  awn-like  point,  hyaline,  about  1  line  long; 
second  glume  larger,  l£  to  2  lines  long;  floral  glumes  narrowly-lanceolate,  scabrous, 
ciliate  011  the  margins,  1-nerved,  2  lines  long,  terminating  in  3  hispid  awns,  middle 
one  4  lines  and  lateral  ones  about  1  line  long;  palet  lanceolate,  acute,  2-nerved, 
hyaline  margins  infolded;  upper  sterile  glumes  same  as  floral  glumes  but  smaller 
and  lateral  awns  sometimes  minute. 

Grain  yellow,  narrowly  triangular,  £  line  long. 

PLATE  XXIV;  a,  spikelet;  b,  floral  glume:  c,  palet;  d,  empty  glumes. 
Texas  to  Mexico. 


TRICH:  TRIFLOEA. 


No.  25. 

TRICHLORIS    VERTICILLATA   Fourn.      (Chloropsis   Blanchardiana 

Gay  in  Herb.') 

Plant  perennial,  mostly  glaucous,  or  light-green,  or  purplish  in  the  inflorescence. 

Culms  tufted  from  somewhat  bulbous  base,  erect  or  sometimes  prostrate  below 
and  rooting  at  the  lower  nodes,  terete,  solid,  smooth,  1  to  2?  feet  tall. 

Leaves;  radical  and  from  sterile  culms,  with  compressed,  hairy- fringed  sheaths 
and  hispid,  flat  or  somewhat  re  volute,  slender-pointed  blades  3  to  8  inches  long;  of 
stem  usually  4;  lower  sheaths  equaling  nodes,  upper  ones  often  much  shorter, 
striate,  hispid,  hairy  along  the  margins,  blade  flat  or  V-shaped  with  revolute  mar- 
gins, hispid  above  and  below  and  with  scattered  white  hairs  above  the  ligule,  which 
is  a  dense  row  of  tine  white  hairs  -3-  line  long. 

Inflorescence  an  umbellate  cluster  of  8  to  12  or  more  narrow,  sessile,  slightly 
spreading  spikes,  3  to  4  inches  long,  with  the  spikelets  narrowly-sessile  in  two 
rows  on  one  side  of  the  hispid  rachis. 

Spikelets  lance-linear,  with  one  fertile  and  one  sterile  flower;  first  glume  linear- 
lanceolate,  acute  or  short  awned,  hyaline,  1-nerved,  i  to  ^  line  long;  second  glume 
ovate,  f  line  long,  with  an  awn  of  equal  length;  third  or  floral  glume  narrowly 
lanceolate,  scabrous  on  back,  obscurely  3-nerved,  1^  lines  long,  terminating  in  3 
scabrous  awns  5  to  9  lines  long;  palet  lance-linear,  ciliate  at  the  rounded  apex, 
hyaline,  2-nerved,  1^  lines  long;  fourth  (sterile)  glume,  cylindrical,  filiform,  1  line 
long,  terminating  in  3  hispid  awns  3  to  6  lines  long. 

Grain  lance-elliptic,  triangular  in  cross  section,  translucent,  light  yellow,  witli 
light  orange  chit,  falling  with  the  spikelet,  entire  except  the  persistent  empty 
glumes. 

PLATE  XXV;  a,  and  b,  spikelets  enlarged. 
Texas,  Arizona  to  Mexico. 


mm 

™  ll/fMfj 


No.  26. 
SCHEDONNARDUS  TEXANUS  Steud.    (Lepturus paniculatus  Nutt.) 

Plant  a  low  straggling  annual. 

Culm  tufted  and  branching  at  base,  spreading,  slender,  terete,  or  compressed, 
hollow,  minutely  pubescent. 

Leaves;  radical  and  from  radical  shoots,  numerous,  folded,  spirally  twisted, 
with  short,  cartilaginous  points;  of  culm  1  or  2  equaled  or  exceeded  by  those  of 
the  base;  sheaths  loose,  compressed,  open  above;  blades  flat  or  folded,  spirally 
twisted,  smooth,  2  to  3  inches  long;  ligule  ovate,  acute,  lacerate,  decurrent  in  sca- 
rious  margins  down  the  sheath. 

Inflorescence  a  loose  racemose  panicle,  the  spikelets  sessile  and  appressed  in 
excavations  in  the  horizontally  spreading  branches,  which  are  1  to  4  inches  long, 
alternate  and  distant  on  the  triangular  hispid  rachis. 

Spikelets  1-flowered,  narrow,  l£  to  2  lines  long;  first  glume  lanceolate,  some- 
times toothed  on  the  margin,  scarious-margined,  £  line  long,  sometimes  1  sided,  1 
prominent  hispid  nerve,  sometimes  excurrent  in  an  awn  one-half  as  long  as  the  glume; 
second  glume  same  but  nearly  twice  as  large;  floral  glume  narrowly  lanceolate, 
acute  or  mucronulate,  3-nerved,  rounded  on  back,  hispid,  on  the  inidnerve,  slightly 
pubescent  at  base,  l£  lines  long;  palet  ovate,  obtuse,  or  slightly  toothed,  round  on 
back,  hyaline,  2-nerved,  li  to  li  lines  long. 

Grain  dark  reddish,  translucent-amber,  with  darker  oblique  chit  extending 
one-third  way  from  base,  narrowly  cylindrical,  1  line  long,  falling  free  or  with 
disarticulate  branch. 

PLATE  XXVI;  a,  branch  with  spikelets  in  position;  b,  spikelet;  c,  second 
empty  glume;  d,  first  empty  glume;  e,  palet;  /,  floral  glume. 

Texas  to  Arizona,  northward  to  Dakota  and  British  America. 


X 


T  Hoi? 


No.   27. 
PAPPOPHORUM  APERTUM  Munro,  in  Herb. 

Plant  perennial,  loosely  tufted  with  somewhat  bulbous  base. 

Culms  erect,  not  branched,  solid,  terete,  smooth,  18  to  30  inches  tall. 

Leaves;  radical  few  and  small;  from  radical  shoots,  with  slightly  hispid 
sheaths,  and  narrow,  involute  blades,  1  to  10  inches  long;  of  culm  3  or  4;  sheaths 
nearly  equaling  or  often  exceeding  internodes,  slightly  hispid;  blade  involute,  his- 
pid above,  2  lines  wide  with  long  tapering  point,  G  to  10  inches  long;  ligule  a  rather 
conspicuous,  loose  hairy  fringe  l£  to  2  lines  long. 

Inflorescence  a  close,  linear,  spike-like,  panicle,  G  to  10  inches  long,  with  short 
branches  below,  none  above,  often  included  at  base. 

Spikelets  oblong,  3-flowered  (upper  one  sterile),  2  lines  long,  on  short  hispid 
pedicels  less  than  $  line  long;  first  glume  lanceolate  acute,  carinate,  hyaline,  mi- 
nutely hispid  on  keel,  1-nerved,  If  lines  long;  second  glume  same  but  i  line  longer; 
floral  glumes  vasiform,  nearly  square  unrolled,  pubescent  especially  below,  1  line 
long,  7-nerved,  each  nerve  terminating  in  a  hispid  awn  2  lines  long,  and  alternat- 
ing with  these  are  7  or  8  slightly  smaller  awns;  sterile  glume  similar  but  half  as 
large  and  raised  on  an  internode  of  the  rachilla  £  line  long;  palet  lanceolate,  lacer- 
ate at  apex,  2-keeled,  1|  lines  long. 

Grain  narrowly  lanceolate,  light  brown,  1  line  long,  falling  with  the  entire 
spikelet,  except  the  persistent  empty  glumes. 

PLATE  XXVII;  a,  spikelet;  b,  empty  glumes;  c,  floral  glume;  d,  palet;  e,  ster- 
ile upper  flowe^ 

There  is  a  variety  of  this  species  with  much  looser  inflorescence,  the  lower 
branches  1  to  2  inches  long,  flowering  mostly  to  the  base  and  subdivided;  spikelets 
purplish. 

Western  Texas  to  Arizona. 


PAPI 


No.  28. 
PAPPOPHORUM  WRIGHTII  Watson.     (P.  boreale  Torr.  non  Griseb.) 

Plant  perennial  (?)  from  densely  tufted,  bulbous  base. 

Roots  fibrous,  flexuous. 

Culms  erect  or  ascending,  geniculate  at  the  lower  nodes,  branching,  slender, 
solid,  terete,  minutely  pubescent  "with  long  white  hairs  at  the  nodes,  10  to  15  inches 
tall. 

Leaves  of  radical  shoots  numerous,  minutely  pubescent,  blade  filiform-involute, 
2  to  4  inches  long;  of  culm  4  to  6;  sheaths  shorter  than  the  internodes,  loose,  open; 
blade  filiform-involute,  1  to  3  inches  long;  ligule  a  dense  line  of  hairs  \  inch  long. 

Inflorescence  a  compact,  spike-like  panicle,  1  to  3  inches  long,  simple,  or  with 
numerous  short  appressed  branches  below. 

Spikelets  on  short  hispid  pedicels,  about  3-flowered,  1  line  long;  empty  glumes 
lanceolate,  acutish,  5-nerved;  hyaline,  sparsely  pubescent,  f  line  long;  second 
glume  same  but  £  longer;  floral  glumes  broadly  oval,  pubescent,  1  line  long  and 
nearly  as  broad;  5  nerves  terminating  in  feathered  awns  li  lines  long,  purple  at 
base,  4  similar  intermediate  awns  alternating;  sterile  glume  similar  but  smaller 
and  raised  on  a  longer  internode  of  the  rachilla;  palet  elliptical,  hyaline,  2 -keeled, 
nerves  rather  inconspicuous,  f  line  long. 

Grain  about  oval,  dull-yellow,  falling  with  the  floret. 

PLATE  XXVIII;  a,  spikelet  dissected;  6,  sterile  flowers;  c,  floral  glume;  d,  palet, 
Texas  to  California  and  Mexico, 


PAPPOPHOPJJM  "//EIGHTH.  Wazson, 


No.  29. 
COTTEA  PAPPOPHOROIDES  Kunth. 

Plant  perennial  from  a  short,  scaly  rootstock,  light  green  or  often  purplish  in 
the  infloresence  and  lower  sheaths. 

Culms  loosely  tufted  at  base,  erect  or  somewhat  spreading,  branching,  hollow, 
terete,  pubescent,  1  to  2  feet  tall. 

Leaves;  radical  and  from  radical  shoots  few  and  small ;  of  culm  7  to  10,  sheaths 
close,  minutely  cinerous  pubescent,  nearly  equaling  or  usually  exceeding  the  inter- 
nodes;  blade  flat  or  involute  toward  the  tapering  point,  somewhat  scabrous  on 
both  sides,  1-J  to  2  lines  wide,  3  to  6  inches  long;  ligule  a  minute  hairy  fringe. 

Inflorescence  a  rather  close,  or  becoming  loose,  lanceolate  or  narrowly  pyra- 
midal panicle,  3  to  6  inches  long,  peduncle  but  little  exserted,  rachis  pubescent, 
nearly  terete;  branches  mostly  alternate,  flower-bearing  nearly  to  the  base,  slightly 
spreading,  1  to  2  inches  long,  bearing  the  spikelets  on  short  pubescent  pedicels. 

Spikelets  obovate,  flat,  7- to  10-flowered,  3  to  4  lines  long;  empty  glumes  oblong 
or  oblong-ovate,  nearly  equal,  2  lines  long;  first  glume  irregularly  3-toothed  at 
apex,  about  13-nerved,  pubescent  on  back,  margins  hyaline;  second  glume  acutish 
or  short  awned,  about  9-nerved,  with  hyaline  margins,  less  pubescent  than  first 
glume;  floral  glumes  obovate,  1  to  H  lines  long,  pubescent  especially  at  base,  about 
15-nerved,  cleft  above  into  11  narrow  divisions,  the  outer  more  deeply  cleft,  and 
ciliate  on  the  margins,  with  long  white  hairs,  each  terminating  in  a  hispid  awn  -£  to 
1^  lines  long;  palet  lanceolate,  with  2  pubescent  nerves  continuing  and  connivent 
about  the  cleft  apex,  narrow  hyaline  margins  infolded,  l£  lines  long. 

Grain,  dull  whitish  yellow,  oblong,  slightly  curved,  falling  with  the  disartic- 
ulated spikelet  or  easily  escaping  free. 

PLATE  XXIX;  a,  spikelet;  b,  empty  glumes;  c,  floral  glumes;  c1,  part  of  apex 
of  floral  glume  enlarged;  d,  palet;  dl,  apex  of  palet.  The  figure  b  does  not  show 
the  full  number  of  nerves. 

Texas  to  Arizona  and  Mexico. 


No.  30. 
SCLEROPOGON  KARWINSKIANUS  Benth.     (Lesourdia  Yourn.) 

Plant  perennial,  from  horizontal  rootstock,  culms  of  the.  season  often  rising 
from  branches  thickly  covered  with  pubescent  scales  which  are  the  bases  of  the 
leaf  sheaths  of  previous  seasons;  new  growth,  rather  glaucous  throughout. 

Culm  ascending,  slender,  terete,  smooth,  branching  below,  6  to  12  inches  tall. 

Leaves  of  sterile  culms,  and  radical,  numerous,  with  flat  blades  1  to  2  inches 
long;  of  culm  2  or  3;  sheaths  usually  much  shorter  than  internodes,  close,  smooth; 
blade  flat  or  folded,  hispid  on  the  back  of  the  miduerve  toward  the  rigid  point,  1 
line  wide,  I  to  2  inches  long:  ligule  a  dense  row  of  minute  stiff  bristles,  A  line  long. 

Inflorescence  unisexual,  flowers  on  distinct  culms.  Male  flowers  forming  a  short, 
close  panicle  of  o  to  8  spikelets  on  short  pedicels,  often  subtended  by  a  narrow 
bract  on  the  rachis.  Spikelets  15-  to  30-flowered,  2  to  3  lines  wide,  -|  to  li  inches 
long,  rachilla  glabrous,  internodes  f  line  long;  first  and  second  glumes  equal,  nar- 
rowly lanceolate,  acute,  carinate,  scarious,  smooth,  1-nerved,  2  lines  long;  floral 
glumes  lance-ovate,  acute  or  often  with  short  awn  and  2  or  4  teeth  at  apex,  scari- 
ous, 3-nerved,  smooth,  2%  to  3£  lines  long;  palet  oblong,  flat,  with  margins 
infolded,  scabrous  on  the  two  nerves. 

Female  flowers  forming  an  irregular  narrow  panicle  of  3  to  7  few-flowered 
spikelets,  each  subtended  by  a  narrow  bract;  first  glume  narrowly  lanceolate,  with 
long,  tapering  point,  smooth,  obscurely  5-nerved,  4  to  6  lines  long;  second  glume 
lanceolate,  smooth,  3-nerved,  6  to  8  lines  long;  internodes  of  rachilla  1  line  long, 
stipe  bristly  pubescent;  floral  glume  linear,  4  to  5  lines  long,  the  3  nerves  termi- 
nating in  slender  twisted  awns,  2  to  5  inches  long,  with  membranaceous  expan- 
sions at  the  sides  between  each  awn;  palet  lanceolate,  acute  or  somewhat  lacerate 
at  the  apex,  hispid  on  the  2  nerves  above,  scarious  margins  folding  closely  over  the 
grain,  4  to  5  lines  long. 

Grain  light  amber  color,  cylindrical,  bifid  at  top,  2  lines  long. 

PLATE  XXX;  1,  staminate  plant;  2,  pistillate  plant;  a,  staminate  flower;  b, 
pistillate  spikelets  partly  dissected  and  the  awns  cut  off;  c,  floral  glume  of  pistil- 
late flower  spread  out,  dorsal  view. 

Western  Texas  and  Arizona  to  Mexico. 


No.  31. 
MUNROA  SQUARROSA  Torr.     (Crypsis  aquarrosa  Nutt.) 

Plant  annual,  low,  glaucous,  more  or  less  wooly  throughout  or  glabrous  except 
at  the  nodes. 

Root  slender,  filiform. 

Culms  tufted,  spreading,  often  prostrate,  fasciculately  branched,  primary  stems 
2  to  4  inches  long,  secondary  shorter,  naked  internodes  striate,  angular,  and  hispid 
on  the  angles. 

Leaves  ;  radical  and  from  sterile  culms  numerous,  with  flat  blades  i  to  1  inch 
long ;  of  stem  several,  crowded  with  the  spikelets  at  the  nodes,  or  ends  of  branches  ; 
sheaths  short,  membranaceous,  7-nerved,  ciliate ;  blade  flat,  hispid,  ciliate,  acute, 

1  to  1  inch  long ;  ligule  a  row  of  short,  fine  hairs. 

Inflorescences  hidden  in  the  tufts  of  leaves  at  the  nodes  and  ends  of  branches. 

Spikelets  3-  to  5-flowered,  crowded  in  dense  clusters  at  the  apex  of  the  branches  ; 
first  glume  narrowly  lanceolate,  hyaline,  1  -nerved,  1£  lines  long ;  second  glume 
same  but  ^  line  longer  ;  floral  glumes  herbaceous,  becoming  coriaceous,  3-nerved, 
tufts  of  pubescence  on  lateral  nerves  and  near  base  of  keel,  entire  or  2-toothed, 

2  to  2^  lines  long,  the  central  nerve  excurrent  in  a  short  awn  ;  palet  narrow,  hyaline, 
pubescent  on  the  two  nerves  complicate  ;  upper  flower  in  spikelets  usually  sterile. 

Grain  translucent,  cream- white,  lance-oval,  £  to  \  line  long. 

PLATE  XXXI ;  1,  cluster  of  spikelets ;  2,  spikelet ;  3,  second  empty  glume ; 
4,  first  empty  glume ;  5,  floral  glume,  side  view,  and  6,  same  spread  out,  dorsal 
view ;  7,  palet ;  8,  pistil  ;  9,  mature  grain. 

A  low,  tufted  grass  growing  on  elevated  plains  from  Mexico  to  British  America, 
usually  associated  with  Buchloe  dactyloides,  but  not  liked  by  cattle. 


No,  32, 

TRIODIA  A  CUMIN  ATA  (Munro.)  Vasey.    (Tricuspis  acuminata  Munro  in 

Herb.) 

Plant  annual  or  short-lived  perennial,  tufted  with  rather  bulbous  base. 

Culms  erect,  slender,  not  branching,  slightly  compressed,  smooth  or  sparsely 
pubescent,  6  to  12  inches  tall. 

Leaves  ;  radical,  numerous,  with  short,  tapering,  compressed  sheaths,  and 
flat  or  folded,  abruptly  pointed,  pubescent  blades,  2  to  3  inches  long  ;  of  culms  2 
or  3  ;  sheaths  mostly  shorter  than  internodes,  close,  nearly  smooth  ;  blades  like 
those  of  radical  leaves  but  shorter  ;  ligule  a  minute,  bristle-like  fringe. 

Inflorescence  a  contracted,  close  head  or  panicle,  1  to  2  inches  long,  light  colored 
or  often  purplish,  composed  of  7  to  15  nearly  sessile,  densely  flowered  spikelets 
or  branches,  i  to  f  inch  long,  sometimes  interrupted  below. 

Spikelets  lanceolate,  compressed,  9-.  to  12-flowered,  2  to  3  lines  wide,  5  to  7  lines 
long  ;  internode  of  pubescent  rachilla  less  than  i  line  long  ;  first  glume  ovate, 
acuminate,  or  awl-pointed,  carinate,  scarious,  smooth,  1-nerved,  2  to  2i  lines  long  ; 
second  glume  same  but  nearly  4-  line  longer  ;  floral  glumes  ovate,  acuminate, 
slightly  obtuse  or  somewhat  2-  toothed  at  apex,  carinate,  membranceous,  pubescent 
on  the  3  nerves  at  base,  2  to  2|  lines  long,  2  lateral  nerves  marginal,  midnerve  ex- 
current  in  a  short  slender  awn  :  palet  lanceolate,  finely  pubescent  on  the  two  prom- 
inent keels  and  at  base,  1  to  l£  lines  long. 

Grain  irregularly  spindle  shaped,  light-green,  |  line  long. 


^.E  XXXII  ;  a,  spikelet  ;  b,  empty  glumes  ;  c,  floral  glume  ;  d,  palet. 
Texas  to  Arizona,  and  Mexico. 


No.  33. 
TRIODIA    ALBESCENS  (Munro.).    (Tricuspis  albescens  Munro  in  Herb.) 

Plant  perennial,  with  slightly  thickened  base,  smooth  and  often  glaucous 
throughout. 

Roots  coarse. 

Culms  loosely  tufted,  erect,  solid,  terete,  not  branching,  15  to  30  inches  tall. 

Leaves;  radical,  sheaths  short  and  open;  blades  flat  or  folded,  involute,  slen- 
der-pointed, 2  to  3  lines  wide,  5  to  12  inches  long;  of  culm  2  to  4,  sheaths  shorter 
than  internodes,  open  above;  blades  like  those  of  radical  leaves;  ligule  a  dense  line 
of  short,  fine  hairs. 

Inflorescence  a  slender,  contracted,  close  panicle,  somewhat  interrupted  below, 
erect  or  slightly  nodding,  ^  inch  wide,  4  to  8  inches  long;  branches  appressed,  un- 
equal, £  to  1^  inches  long,  bearing  along  their  entire  length  rather  crowded  short- 
pedicelled  spikelets. 

Spikelets  oval,  compressed,  8-  to  12-flowered,  2-£  to  3  lines  long  and  f  as  wide; 
first  and  second  glumes  nearly  equal,  second,  slightly  larger,  broadly  ovate, 
acute,  carinate,  hyaline,  smooth.  1-nerved,  ]-£  lines  long;  internodes  of  rachis 
curved,  i  line  long  or  less;  floral  glume  broadly-elliptical,  3-nerved,  emarginate  or 
nearly  entire,  hyaline,  smooth,  or  nearly  so,  midnerve  slightly  if  at  all  excurrent, 
lateral  nerves  not  marginal;  palet  broadly  ovate,  obtuse,  2-keeled  with  the  mar- 
gins folded  flat,  li  lines  long. 

Grain  elliptical,  yellow,  i  line  long. 

PLATE  XXXIII;  a,  spikelets;  b,  empty  glumes;  c,  floral  glumes;  d,  palet. 
Texas  and  New  Mexico. 


No.  34. 
TRIODIA     ERAGROSTOIDES  Vasey  &  Scrib. 

Plant  annual  or  short-lived  perennial,  with  slightly  thickened  base. 

Culms  erect,  branching,  solid,  terete,  smooth,  2  to  3  feet  tall. 

Leaves;  radical,  few;  of  culm  5  to  9,  sheaths  usually  exceeding  the  iiiternodes, 
rather  loose  and  open  above,  striate  and  slightly  scabrous,  blades  flat  or  involute 
toward  the  long  tapering  point,  scabrous  on  both  sides.  2  to  3  lines  wide,  G  to  10 
inches  long;  ligule  membranaceous,  truncate,  lacerate,  tawny,  1  line  long. 

Inflorescence  a  loose,  spreading,  lance-ovate,  or  pyramidal,  erect  or  drooping 
panicle  8  to  12  inches  long;  rachis  angular,  hispid  near  top,  branches  mostly 
alternate,  slender,  scabrous  only  toward  the  extremities,  sometimes  reflexed  at 
maturity,  3  to  6  inches  long,  bearing  the  nearly  solitary  spikelets  on  slender,  scab- 
rous pedicels  1  to  3  lines  long. 

Spikelets  oblong-ovate,  compressed,  7-  to  9-flowered,  2  to  3  lines  long;  first 
glume  linear-lanceolate,  acute  or  acuminate,  1-nerved.  1  line  long;  second  glume 
ovate-lanceolate,  acuminate  and  longer;  internodes  of  slender  glabrous  rachilla 
articulating  above,  i  line  long;  floral  glumes  oblong,  truncate  or  slightly  2-lobed, 
mucronate,  rounded  on  back,  membranaceous,  often  purplish,  pubescent  near  the 
base  on  the  3  nerves,  lateral  nerves  near  the  margins,  1  line  long;  palet  lance- 
oblong,  truncate,  minutely  ciliate,  .rnembranaceous,  smooth,  2-keeled,  scarcely  1 
line  long. 

Q-rain  oblong,  angular,  2-horned  at  apex,  opaque,  brown,  falling  with  spike- 
let,  usually  disarticulate  above  empty  glumes. 

PLATE  XXXIV;  6,  spikelet  enlarged. 

Florida,  Texas  to  Mexico.  A  large  leafy  grass  which  promises  to  be  servicea- 
ble in  agriculture. 


k 


\  \ 

^  \ 

\ 

^      ^ 


No.   35. 
TRIODIA  GRANDIFLORA  Vasey. 

Plant  perennial,  with  tufted  bulbous  base,  rather  glaucous  or  minutely  cinerous- 
pubescent  throughout. 

Culms  slender,  erect,  not  branching,  often  geniculate  at  the  hairy  nodes,  terete, 
sparingly  pubescent,  1  to  2  feet  tall. 

Leaves;  radical,  numerous  with  compressed,  equitant,  hairy-fringed  sheaths 
and  flat  or  folded,  white-margined,  pubescent,  obtuse  or  abruptly  pointed  blades, 
2  to  4  inches  long;  of  culm  3,  rarely  2  or  4;  sheaths  half  as  long  as  internode, 
close,  slightly  pubescent  or  nearly  glabrous;  blades  like  those  of  radical  leaves  but 
upper  ones  shorter  and  erect. 

Inflorescence  a  close,  contracted,  head-like  white  panicle,  composed  of  numer- 
ous, nearly  sessile  branches,  1  to  2  inches  long;  rachis  and  branches  somewhat 
pubescent,  or  scabrous. 

Spikelets  nearly  sessile,  oblanceolate,  compressed,  4-  to  6-flowered,  2  lines  wide, 
4  to  5  lines  long;  first  glume  lance-ovate,  acute,  carinate,  membranaceous,  minutely 
scabrous  on  keel,  1-nerved  or  sometimes  3-nerved  on  lower  spikelets,  2  to  3  lines 
long;  second  glume  same,  but  ciliate  at  base,  always  1-nerved,  and  1  line  longer; 
floral  glume  lance-ovate,  obtuse  and  minutely  ciliate,  or  with  2  narrow  lobes  at 
apex,  pubescent  below,  profusely  ciliate,  3-nerved,  2  to  3  lines  long;  hispid  mid- 
nerve  excurrent  in  an  awn  ^  to  1  line  long;  palet  broadly  lanceolate,  pubescent  at 
the  base  and  on  the  2  prominent  keels,  1  to  1£  lines  long. 

Grain  not  present  in  the  specimens  examined. 

PLATE  XXXV;  a  and  6,  floral  glumes  showing  the  extremes  of  variation  at 
the  apices;  c,  palet. 

This  species  has  been  called  T.  avenacea  H.  B.  K.,  from  which  it  differs  in  its 
much  larger  size,  and  in  its  flowers,  as  is  shown  by  a  comparison,  of  the  figure  in 
H.  B.  K. 

Western  Texas  to  Arizona  and  Mexico, 


\ 


No.  36. 
TRIODIA  NEALLEYI  Vasey. 

Plant  perennial,  tufted,  with  a  bulbous  base. 

Culms  erect,  slender,  not  branched,  terete,  smooth,  1  to  2  feet  high,  nodes  ciliate. 

Leaves;  radical  with  pubescent,  fringed,  scarious-margined  sheaths,  tapering 
into  narrow,  folded,  nearly  smooth  blades  2  to  6  inches  long;  of  culm  3  or  4,  sheaths 
close,  smooth,  lower  ones  equaling  or  exceeding  internodes,  upper  much  shorter; 
blades  flat  or  folded,  nearly  smooth,  1  to  3  inches  long;  ligule  a  narrow,  callous 
line  with  a  loose  fringe  of  hairs. 

Inflorescence  a  dense  spike-like  panicle,  white,  1  to  2%  inches  long,  the  branches 
^  to  1  inch  long,  alternate,  closely  appressed. 

Spikelets  broadly  oblanceolate,  compressed,  1-J  to  2%  lines  wide,  2%  to  3  lines, 
long, "4-  to  7-flowered;  first  glume  ovate,  acute,  carinate,  translucent,  smooth,  about 
2  lines  long;  second  glume  same,  but  £  line  longer;  floral  glumes  oblong,  truncate, 
translucent,  profusely  ciliate  on  the  margins  and  pubescent  on  the  back  below, 
2-lobed.or  cleft  one-third  way  to  base,  the  two  minutely  ciliate  lobes  equaled  or 
exceeded  by  the  intermediate  awn,  3-nerved,  lateral  nerves  marginal;  palet  lance- 
olate, strongly  arched,  thin,  pubescent  on  the  two  prominent  keels. 

Grain  pale  translucent-green,  shaped  like  the  quarter  of  a  sphere  with  brown- 
ish opaque  projection  extending  along  the  axis,  f  line  long. 

PLATE  XXXVI;  a,  spikelet;  b,  empty  glumes;  c,  floral  glume,  dorsal  and  side 
view;  d,  palet. 

Thus  far  collected  only  in  Texas,  by  G.  C.  Nealley,  for  Whom  it  is  named. 


No.  37. 
TRIODIA  PULCHELLA  H.  B.  K.     ( Uralepis  pulchella  Kth.) 

Plant  a  low,  tufted  perennial,  with,  bulbous  base,  arising  from  a  slender  creep- 
ing rootstock. 

Culms  spreading,  f asciculately  branched,  at  the  extremity  of  long,  naked  inter- 
nodes. 

Leaves;  radical  and  of  culm  alike,  numerous,  clustered  at  the  base,  and  around 
the  fascicles  of  branches  leaving  the  internodes  naked;  sheaths  short,  open,  taper- 
ing, scarious;  blades  narrow,  folded  and  in  volute;  ligule  a  minute  fringe,  decurrent 
down  the  inembranaceous  margin  of  the  sheath. 

Inflorescence,  small  clusters  of  light-colored  spikelets  terminating  the  short 
clustered  branches. 

Spikelets  lanceolate,  compressed,  7-  to  10-flowered,  2  lines  wide,  3  to  4  lines  long; 
internode  of  rachilla  articulate  below,  -£  line  long;  first  glume  lance-ovate,  acumi- 
nate, carinate,  hyaline,  smooth,  1-nerved,  2  to  2|  lines  long;  second  glume  same 
but  |  line  longer;  floral  glume  oblong,  2  lines  long,  cleft  above  half  way  to  base  or 
more,  making  2  long  narrow  margined  lobes,  between  which  the  midrib  is  extended 
as  an  awn  longer  than  the  lobes,  2  lateral  nerves  nearly  marginal,  profusely  ciliate, 
pubescent  below;  palet  oblong,  truncate,  thin,  pubescent  below,  and  on  the  2  keels. 

Grain  pear  shaped,  translucent,  light  yellowish  color,  with  opaque,  brownish 
base  i  line  long. 

PLATE  XXXVII;  1,  young  plant;  2,  plant  in  flower;  3,  at  maturity;  a,  spikelet; 
ft,  empty  glumes;  c,  floral  glume,  dorsal  and  side  views;  d,  palet. 

Texas  to  California  and  Mexico. 


No.  38. 

TRIODIA  STRICTA  (Nutt.)  Vasey.    (Tricuspis  stricta  Thurb.     Windsoria 

stricta  Nutt.) 

Plant  coarse,  apparently  perennial,  glabrous  throughout  except  near  the 
ligule. 

Culms  erect,  few  in  a  place,  tufted,  with  sterile  culms  at  base,  not  branched, 
terete,  thick,  2  to  3  feet  tall. 

Leaves;  radical  and  from  radical  shoots  numerous,  the  long  tapering  sheaths 
continuing  with  but  slight  constriction  at  the  ligule,  into  the  flat  or  involute  smooth 
blade,  2  lines  wide,  8  to  12  inches  long;  of  culm  4  or  5,  sheaths  usually  exceeding 
the  internodes,  open  above,  blade  like  those  of  radical  leaves,  ligule  an  inconspic- 
uous, tawny  fringe. 

Inflorescence  a  constricted,  dense,  erect,  spike-like  panicle,  4  to  12  inches  long, 
branches  sessile,  alternate,  appressed,  i  to  1  inch  long. 

Spikelets  nearly  sessile,  obovate,  compressed,  5-  to  8-flowered,  \\  to  2  lines 
wide,  2  to  2|  lines  long;  first  and  second  glumes  equal,  narrowly  lanceolate,  longer 
than  the  spikelet,  acute,  or  irregularly  toothed  at  apex,  carinate,  membranaceous, 
smooth,  1-nerved,  2  to  3  lines  long;  floral  glumes  oblong,  toothed  at  apex,  obtuse, 
membranaceous,  3-nerved,  lateral  nerves  nearly  marginal,  middle  one  slightly 
excurrent,  all  pubescent  below,  1  to  \%  lines  long;  palet  elliptical,  obtuse,  arched, 
thin,  the  2  keels  minutely  velvety  pubescent. 

Grain  obovate,  2-horned  at  summit,  opaque,  yellow,  f  line  long. 

PLATE  XXXVIII;  a,  spikelet;  6,  empty  glumes;  c,  floral  glume  dorsal  and 
side  views;  d,  palet,  dorsal  and  ventral  views. 

Louisiana  to  Texas  and  Indian  Territory. 


No.   39. 
TRIODIA  TEXANA  Watson. 

Plant  perennial,  with  somewhat  bulbous,  tufted  base. 

Culms  erect,  simple  or  sparingly  branched,  slightly  geniculate,  terete,  slightly 
pubescent,  l£  to  2  feet  tall. 

Leaves;  radical  numerous,  with  short,  smooth  sheaths  and  involute  blades  3 
to  6  inches  long;  of  culm  3  or  4;  sheaths  usually  exceeding  internodes,  close,  nearly 
smooth;  blades  flat  or  becoming  involute,  slender,  pointed,  smooth  or  slightly 
pubescent,  2  or  3  lines  wide,  6  to  10  inches  long;  ligule  a  minute  fringe  with  longer 
hairs  at  the  sides. 

Inflorescence  a  loose,  nodding  or  flexuous  panicle,  3  to  5  inches  long;  branches 
mostly  alternate  and  spreading,  slender,  smooth,  1  to  2  inches  long,  divided  and 
bearing  beyond  the  middle  3  to  5  or  more  pedicellate  spikelets. 

Spikelets  large,  oblong,  somewhat  compressed,  purplish,  6-  to  9-flowered,  3  to  5 
lines  long;  first  glume  ovate-lanceolate,  acute  or  irregularly  toothed,  carinate,  hya- 
line, smooth,  1-nerved,  1  to  1  1£  lines  long;  second  glume  same  but^  line  longer; 
internode  of  rachilla  curved,  glabrous,  articulate  above,  £  line  long;  floral  glumes 
nearly  orbicular,  slightly  lacerate  above,  membranaceous,  pubescent  toward  the 
base  of  the  3  nerves,  2  lateral  nerves  not  marginal,  about  2  lines  long;  palet  broad 
at  base,  narrowed  above,  obtuse,  2  keeled,  smooth,  If  lines  long. 

PLATE  XXXIX;  a,  spikelet;  b,  empty  glumes;  c,  floral  glume;  d,  palet,  ven- 
tral view. 

Louisiana  to  Texas,  New  Mexico  and  Mexico. 


No.  40. 

TRIODIA  TRINERVIGLUMIS  (Munro)  (Tricuspis  trinerviglumis  Munro 

in  Herb.) 

Plant  perennial,  with  slightly  thickened  tufted  base. 

Culms  erect  or  geniculate  below,  rarely  branching,  terete,  hispid,  2  to  3  feet  tall. 

Leaves;  radical  and  of  radical  shoots  numerous,  with  loose,  pubescent  sheaths 
and  involute,  hispid,  often  pubescent  blades,  3  to  6  inches  long;  of  culm  4  to  6; 
sheaths  longer  than  internodes,  open  above,  upper  ones  nearly  smooth;  blades  like 
those  of  radical  leaves;  ligule  an  inconspicuous  fringe. 

Inflorescence  a  narrow,  erect,  spike-like  panicle,  4  to  8  inches  long;  branches 
erect,  simple,  almost  appressed,  |  to  2  inches  long,  or  often  reduced  to  single 
spikelets  a  little  distant,  or  interrupted. 

Spikelets  oblong  or  oblanceolate,  but  little  compressed,  7-  to  9-flowered,  3  to  5 
lines  long;  first  glume  lanceolate,  obtuse  or  nearly  acute,  carinate,  scarious,  7- 
nerved,  2  to  3  lines  long;  second  glume  lance-ovate,  acute,  carinate,  scarious,  sca- 
brid,  hispid  on  keel,  3-nerved,  2£  to  3£  lines  long;  internode  of  rachilla  stout, 
pubescent,  articulate  above,  %  line  long;  floral  glumes  oblong-ovate,  obtuse,  emar- 
ginate,  mucronate  or  entire  at  apex,  3-nerved,  pubescent  below,  lateral  nerves 
vanishing  bef 6re  reaching  the  margin,  palet  ovate,  obtuse,  pubescent  on  the  2  keels, 
1|  lines  long. 

Grain  ovate-conical,  deeply  hollow  on  one  side,  dark-brown,  punctate,  1-J  lines 
long. 

PLATE  XL;  a,  spikelet;  &,  and  b' ',  empty  glumes;  c,  floral  glume  dorsal  and 
side  views;  d,  and  e,  palet,  ventral  and  side  views. 

Prevails  throughout  Texas,  westward  to  Arizona,  and  northward  to  Colorado. 
Apparently  not  of  great  agricultural  importance.  Tricuspis  mutica  Torr.  appears 
to  be  a  smaller  form,  with  shorter,  interrupted  panicle. 


No.  41. 
DIPLACHNE    FASCICULARIS  P.  B.     (Leptochloa  fascicularis  Gray.) 

Plant  annual,  glaucous  or  light  green,  more  or  less  purplish  on  the  sheaths 
and  inflorescence. 

Roots  numerous,  coarse. 

Culms  few,  loosely  tufted  at  base,  erect  or  decumbent,  branching,  striate, 
smooth,  2  to  3  feet  tall. 

Leaves;  radical  and  from  sterile  culms  with  thin,  smooth,  striate,  equitant 
sheaths  and  slender  involute,  slightly  hispid  blades,  1  line  wide  unrolled,  6  to  12 
inches  long ;  of  stems  3  or  4 ;  sheaths  usually  exceeding  internodes,  smooth ;  blade 
like  that  of  radical  leaves,  upper  one  exceeding  panicle  and  sheathing  its  base ; 
ligule  membranaceous,  triangular,  ovate,  acute,  entire,  wider  than  blade,  H  to  2 
lines  long. 

Inflorescence  a  loose,  narrow,  spreading  panicle,  included  at  base  in  upper 
sheath,  6  to  8  inches  long  ;  of  many  linear,  spike-like  spreading  branches,  hispid, 
mostly  alternate,  2  to  4  inches  long,  bearing  8  to  15  nearly  sessile,  appressed  spike- 
lets  ;  general  rachis  angular,  hispid. 

Spikelets  linear-oblong,  or  lanceolate  at  maturity,  flattened,  6-  to  9-flowered,  3^ 
to  4  lines  long ;  internodes  of  articulate  rachilla,  -£  line  long ;  first  glume  varying 
from  ovate-lanceolate  to  linear,  barely  acute,  or  acuminate,  hispid  on  back, 
1-nerved,  1  to  H  lines  long ;  second  glume  lanceolate  to  oblong,  longer  and  often 
somewhat  3 -toothed  or  lacerate  at  the  apex ;  floral  glumes  linear-oblong,  acute, 
ciliate  on  the  lower  third  of  the  nerve,  and  pubescent  at  the  base,  1£  to  2  lines  long, 
3-nerved,  2  lateral  nerves  marginal,  ending  in  rather  inconspicuous  teeth,  mid- 
nerve  excurrent  in  a  hispid  awn  nearly  •£  line  long ;  palet  linear,  with  two  prom- 
inent pubescent  nerves,  narrow,  hyaline,  infolded  margins,  and  truncate  or  slightly 
rounded,  minutely  ciliate  apex. 

Grain  surrounded  with  rather  loose,  hyaline  pericarp ;  salmon  pink  with  small 
garnet  scar  at  base,  flat,  lanceolate,  1  line  long ;  readily  shelling  out  of  flower  as 
the  spikelet  falls. 

PLATE  XLI ;  a,  spikelet ;  &,  empty  glumes ;  c,  floral  glume,  dorsal  and  side 
view;  d,  palet. 

This  species  presents  considerable  variation  in  the  spikelets,  forming  probably 
several  varieties. 

It  is  extensively  distributed  over  the  country,  both  north  and  south,  but  be- 
comes abundant  in  Texas  and  westward,  also  in  Mexico. 


D1PLACHNE    FASCiCULARIS,  P.B. 


No.  42. 
DIPLACHNE  IMBRICATA  (Thurb. )  Scrib.  (LeptochloaimbricataThur}).) 

Plant  annual  or  short-lived  perennial  from  bulbous  base,  somewhat  glaucous, 
purplish  on  the  sheaths  and  with  dark  green  panicle. 

Culms  tufted,  erect,  geniculate,  branching,  hollow,  terete,  smooth  or  minutely 
scabrid  near  base  of  panicle,  1  to  2  feet  tall. 

Leaves;  radical  and  of  radical  shoots,  numerous,  with  smooth,  tapering,  com- 
pressed sheaths  and  narrow,  slender  pointed,  folded  or  involute,  hispid  blades,  4 
to  8  inches  long ;  of  culm  3  or  4 ;  ^heaths  striate,  slightly  roughened  on  upper  part, 
open  above,  nearly  equaling  internode ;  blade  like  that  of  radical  leaves  but  usu- 
ally shorter;  ligule  rnembranaceous,  ovate,  acute,  entire,  wider  than  the  blade, 
decurrent. 

Inflorescence  a  rather  close,  narrowly-oblong  panicle,  4  to  6  inches  long,  of 
numerous  linear  branches ;  rachis  angular,  hispid  ;  branches  hispid,  slender, 
mostly  alternate,  slightly  spreading,  1 J  to  2  inches  long,  bearing  on  the  lower  side 
12  to  16  nearly  sessile,  appressed,  and  imbricate  spikelets. 

Spikelets  linear-oblong,  7- to  10-flowered,  2£  to  3  lines  long,  less  than  1  line 
wide ;  internodes  of  glabrous  rachilla  articulate,  £  line  long  ;  first  glume  ovate, 
acute,  carinate,  ciliate,  hispid  on  back,  1-nerved,  f  line  long ;  second  glume  ellip- 
tic-oblong, obtuse,  often  slightly  mucronulate,  1  to  1^  lines  long ;  floral  glume 
oblong,  truncate,  with  two  short  blunt  teeth  at  the  summit,  the  mid-nerve  termin- 
ating in  a  short  mucro,  membranaceous,  pubescent  on  the  lower  half  of  the  lateral 
nerves,  1  line  long ;  palet  lance-oblong,  with  rounded  ciliate  apex,  two  prominent 
pubescent  nerves  and  narrow  infolded  hyaline  margin,  1  line  long. 

Grain  light-brown,  obovate,  falling  with  flower  but  easily  separated. 

PLATE  XLII ;  a,  spikelet ;  b,  empty  glumes ;  c,  floral  glumes,  dorsal  and  side 
view ;  d,  palet. 

Texas,  New  Mexico,  Arizona,  and  southern  California. 


• 


IMBRICATA 


No.  43. 
DIPLACHNE   REVERCHONI  Vasey. 

Plant  a  low  tufted  annual. 

Culms  erect,  slender,  not  branched,  3  to  10  inches  long. 

Leaves  at  base,  numerous,  involute,  setose,  smooth,  1  to  2|  inches  long;  of 
culms  1  or  2  above  base,  mostly  exceeded  by  radical  leaves ;  sheaths  striate,  close, 
smooth;  blade  filiform,  involute;  ligule  a  minute,  hairy  fringe. 

Inflorescence  a  spike- like  panicle,  !•£  to  3  inches  long;  the  nearly  sessile,  ap- 
pressed  spikelets  alternate  along  the  striate  slender  rachis. 

Spikelets  lance-linear,  6-  to  10-flowered,  3  to  4  lines  long;  internode  of  rachilla 
glabrous;  first  glume  ovate,  acute,  carinate,  membranaceous,  1-nerved,  smooth,  1 
line  long;  second  glume  oblong,  obtuse  or  obscurely  toothed  \  line  longer;  floral 
glumes  li  lines  long,  ovate-lanceolate,  membranaceous,  2  teeth  at  apex,  2  lateral 
nerves  slightly  pubescent  at  base,  vanishing  before  reaching  the  margin,  mid-nerve 
excurrent  into  a  minute  hispid  awn  £  line  long;  palet  linear-lanceolate,  2-keeled, 
cleft  at  apex,  minutely  ciliate,  |  line  long. 

Grain  light  amber  color,  narrowly  conical,  falling  with  flower  but  easily  sepa- 
rated. 

PLATE  XLIII;  a,  spikelet;  b,  empty  glumes;  c,  floral  glumes,  dorsal  and  side 
views;  d,  palet. 

Texas  to  Mexico.  First  collected  by  J.  Reverchon,  Texas.  It  has  been  re- 
ferred to  D.  simplex  Doell,  from,  which  I  think  it  differs. 


No.  44. 
DIPLACHNE    RIGID  A  (Munro)  Vasey.     (Leptocliloa  rigida  Munro,  MSS.) 

Plant  perennial,  from  loosely  tufted,  bulbous  base. 

Culms  erect,  terete,  smooth,  not  branching,  1  to  2  feet  tall. 

Leaves;  radical  and  from  radical  shoots  comparatively  few,  with  short,  loose, 
involute,  tapering  sheaths,  and  narrow,  mostly  filiform,  involute,  rigid,  pointed 
blades,  2  to  6  inches  long,  pubescent,  with  few  scattered  hairs;  of  stem  2  or  3; 
sheaths  longer  than  internodes,  close,  smooth,  with  blades  like  those  of  radical 
leaves  ;  ligule  a  prominent  tuft  of  spreading  hairs  1  line  long. 

Inflorescence  a  loose,  spreading  panicle  6  to  12  inches  long ;  rachis  triangular, 
smooth;  branches  distant,  alternate,  spreading  or  horizontal,  triangular,  hispid  on 
the  angles,  with  tuft  of  hairs  at  the  axis,  3  to  6  inches  long,  bearing  5  to  8  distant, 
sessile,  appressed  spikelets. 

Spikelets  oblanceolate,  5-  to  9-flowered,  3£  to  4^  lines  long;  first  glume  lanceo- 
late, acute,  carinate,  rigid,  1-nerved,  hispid  on  keel,  1-j  lines  long;  second  glume 
lanceolate,  acute,  convex,  5-nerved,  2  lines  long;  floral  glumes  lanceolate,  acute, 
barely,  if  at  all,  mucronate,  rigid,  2  lines  long,  smooth,  2  lateral  nerves  vanishing 
before  reaching  the  margin,  palet  oblong,  obtuse,  rigid,  2-keeled,  ciliate,  li  lines 
long,  becoming  strongly  arched. 

Grain  oval,  reddish  brown. 

PLATE  XLIV;  a,  spikelet;  b,  empty  glumes;  c,  floral  glumes,  dorsal  and  side 
view;  d,  palet. 

Texas  and  New  Mexico,  northward  to  Kansas. 


No.  45. 

DIPLACHNE  VISCIDA  Scrib. 

i 

Plant  annual  or  short-lived  perennial,  light  green  or  somewhat  purplish  on 
sheaths  and  inflorescence. 

Culms  erect,  or  low  and  spreading  from  a  tufted  base,  branching  freely,  geni- 
culate,  hollow,  terete,  smooth,  6  to  15  inches  tall. 

Leaves;  radical  and  from  radical  shoots,  few  and  short;  of  stem  3  to  5;  sheaths 
about  equaling  internode,  compressed,  open,  smooth;  blade  flat  or  folded,  with 
slightly  involute  margins,  somewhat  scabrous  above  and  below,  2  to  4  inches  long; 
ligule  membranaceous,  truncate,  lacerate,  |  line  long. 

Inflorescence  a  rather  compact,  narrow,  erect  panicle,  2  to  3  inches  long, 
included  at  the  base;  rachis  angular,  slightly  hispid;  branches  slender,  alternate, 
appressed  or  somewhat  spreading  at  maturity,  ^  to  1  inch  long,  bearing  6  to  10 
appressed,  nearly  sessile  spikelets  on  the  flattened  rachis. 

Spikelets  oblong,  4-  to  6-flowered,  2  to  2i  lines  long;  internode  of  slender 
rachilla  articulate  below,  i  line  long;  first  glume  ovate,  acute,  hyaline,  scabrous 
on  the  single  nerve,  1  line  long;  second  glume  same,  scarcely  %  line  longer;  floral 
glumes  elliptical-oblong,  1  line  long,  2  hyaline  lobes  or  teeth  at  summit  somewhat 
lacerate,  lateral  nerves  nearly  marginal,  pubescent  below,  vanishing  in  the  margin 
in  very  obscure  teeth,  mucronate  awn  of  mid-nerve  i  line  long;  palet  elliptic-oblong, 
hyaline,  with  2  scabrous  nerves  and  shallow  cleft  apex,  minutely  ciliate. 

Grain  light,  opaque  amber,  with  brown  scar,  elliptic,  flattish,  £  line  long, 
falling  with  flower  or  spikelet  nearly  complete. 

PLATE  XLV;  a,  spikelet;  b,  empty  glumes;  c,  floral  glumes,  dorsal  and  side 
views-;  d,  palet. 

New  Mexico,  Arizona,  and  Mexico. 


No.  46. 
ERAGROSTIS  CURTIPEDICELLATA  Buckley. 

Plant  perennial,  tufted  with  numerous  abortive  culms  at  bulbous  base. 

Roots  coarse,  with  dense,  tawny  root  hairs. 

Culms  stout,  erect,  rarely  branching,  terete,  nearly  solid,  smooth,  1  to  2 
feet  tall. 

Leaves  of  sterile  culms  rather  numerous,  with  more  or  less  involute  blades  3 
to  6  inches  long;  of  stem  4  to  8;  sheaths  exceeding  the  internodes,  open  and  rather 
loose  above,  smooth  or  with  few  scattered  hairs  along  the  exposed  margins;  blade 
involute  toward  the  tapering  point,  2  to  2^  lines  wide,  4  to  6  inches  long,  smooth, 
rigid;  ligule  and  throat,  a  row  of  fine  hairs  2  to  2^  lines  long;  sheaths  and  lower 
sides  of  leaf  often  glandular  viscid. 

Inflorescence  an  oblong  pyramidal  erect  panicle  8  to  12  inches  long;  spreading 
branches  3  to  5  inches  long,  much  subdivided,  mostly  alternate,  with  tufts  of 
white  hairs  in  the  axils,  the  solitary  appressed  spikelets  borne  mostly  on  strict, 
hispid  lateral  branchlets. 

Spikelets,  oblong-linear,  less  than  1  line  wide,  2  to  3  lines  long,  often  purplish, 
on  hispid  pedicels  less  than  half  their  own  length,  internodes  of  the  slightly  zigzag 
rachilla  £  line  long;  first  and  second  glumes  ovate,  acute,  carinate,  thin,  herba- 
ceous, 1-nerved,  minutely  hispid  on  keel  above,  £  line  long;  floral  glumes  lanceo- 
late, acute,  prominently  nerved,  f  line  long;  palet  linear,  curved  so  that  its  Jwo 
pubescent  nerves  appear  outside  of  the  flowering  glume. 

Grain,  amber  color,  narrowly  cylindrical,  i  line  long. 

PLATE  XLVI ;  a,  spikelet ;  b,  empty  glumes ;  c,  floral  glume;  d,  palet.  The 
figure  does  not  show  the  hairy  ligule. 

This  species  is  closely  related  to  E.  pectinacea,  being  less  diffuse,  with  shorter 
branches  and  larger  spikelets. 

It  seems  to  be  pretty  closely  confined  to  Texas  and  northward  to  southern 
Kansas. 


No.  47. 
ERAGROSTIS    LUGENS   Nees.     (Eragrostis  pilifera  Scheele  ?) 

Plant  perennial,  from  a  slightly  bulbous  base. 

Hoots  numerous,  rather  coarse,  long,  not  branching,  and  with  few  fibril] SB. 

Culms  tufted,  slender,  erect,  simple,  solid,  nearly  terete,  smooth,  1%  to  3  feet 
tall. 

Leaves;  the  lower  from  abortive  culms,  with  scarious  sheaths,  and  slender, 
involute  blades,  3  to  6  inches  long ;  of  stem  3  or  4;  sheaths  f  length  of  interned e, 
striate.  loose,  smooth;  blade  flat  below,  involute  toward  the  long,  tapering  point, 
a  few  scattered  hairs  above  the  ligule,  otherwise  smooth,  3  to  6  inches  long;  ligule 
a  prominent  line  of  crowded,  white  hairs,  2  lines  long. 

Inflorescence  a  loose,  erect,  pyramidal  panicle,  8  to  10  inches  long,  included  at 
base  in  upper  sheath  when  young,  rachis  grooved  above  each  branch;  branches 
capillary,  mostly  alternate,  minutely  scabrous  toward  the  ends,  and  bearing  a  few 
white  hairs  at  the  axils,  flexuous,  lower  ones  3  to  6  inches  long,  subdividing  nearly 
to  -the  base,  bearing  15  to  20  spikelets  on  the  long,  filiform  branchlets. 

Spikelets  linear-lanceolate,  4  to  5  lines  long,  on  slender  pedicels  as  long  as  them- 
selves, or  much  longer,  5-  to  11-flowered;  internodes  of  rachilla  £  line  long;  first 
and  second  glumes  nearly  alike,  scarious  margined,  broadly  ovate,  nearly  acute, 
obscurely  1-nerved,  1  .line  long;  •  floral  glumes  scarious  above,  broadly  ovate, 
obscurely  3-nerved,  smooth,  1  to  l£  lines  long;  palet  linear,  membranaceous, 
arched,  smooth,  1  line  long. 

Grain  reddish  brown,  rhomboidal,  \  line  long. 

PLATE  XLVII;  a,  spikelet  with  pedicel;  &,  empty  glumes;  c,  floral  glume 
dorsal  and  side  views;  d,  palet  and  stigmas.  The  plate  does  not  represent  the  hairs 
of  the  ligule. 

Texas  and  New  Mexico. 

This  species  is  very  near  our  E.  capillaris,  and  varies  considerably  in  the  length 
of  leaves  and  size  of  panicle;  it  is  also  near  Eragrostis  Mexicana  Link. 


\ 


No.  48. 
ERAGROSTIS    OXYLEPIS   Torr.     (Poa  interrupt®  Nutt.) 

Plant  annual  or  a  short-lived  perennial,  from  slightly  enlarged  base,  light 
green,  usually  tinged  with  purple,  especially  in  the  inflorescence. 

Roots  with  abundant  coarse  root  hairs,  sometimes  branching. 

Culms  ascending,  prominently  geniculate,  hollow,  not  branching,  terete, 
smooth,  1  to  2  feet  tall. 

Leaves  numerous;  from  abortive  culms,  involute,  8  to  12  inches  long;  of  stem 
2  or  3;  sheaths  nearly  equaling  or  usually  exceeding  the^  lower  internodes,  smooth, 
open  above  but  appressed  to  culm,  blade  involute  with  slender  rigid  point,  3  to  6 
inches  long;  ligule  a  dense  tuft  of  fine  hairs  2  lines  long. 

Inflorescence  an  irregular,  oblong  panicle,  of  dense  clusters  of  spikelets  nearly 
sessile  on  the  branches,  which  are  short  above,  the  lower  sometimes  1  to  3  inches 
long,  erect,  and  at  irregular  intervals  on  the  rachis. 

Spikelets  oblong-lanceolate,  compressed,  2  to  3  lines  wide,  7  to  9  lines  long,  20- 
to  30-nowered;  internodes  of  zigzag  rachilla  i  line  long,  with  minute  pubescence  at 
each  node;  first  glume  narrowly  ovate,  acute,  carinate,  1-nerved,  hispid  on  the 
keel,  scarcely  1  line  long;  second  glume  same  as  first  but  £line  longer;  floral  glumes 
ovate,  acute,  carinate,  hispid  on  keel  above,  3-nerved,  1-J  to  2  lines  long;  palet 
elliptical,  cleft  at  apex,  ciliate  on  the  two  reflexed  arched  marginal  nerves,  1  to  li 
lines  long. 

Grains  not  abundant,  translucent  amber  color,  narrowly  conical,  nearly  £ 
line  long. 

PLATE  XL VIII,  1;  a,  empty  glumes;  b,  floral  glume  dorsal  and  side  views; 
c,  palet. 

PLATE  XLVIII,  2;  another  form,  with  panicle  more  interrupted  and  branches 
longer;  a',  empty  glumes;  b',  floral  glume,  dorsal  and  side  views;  c',  palet. 

Gulf  States,  Texas,  and  northward  to  Kansas. 


No.  49. 
ERAGROSTIS  PURSHII  Shrad. 

Plant  annual,  diffuse,  spreading  from  a  tufted  base. 

Roots  sometimes  secondary  from  lower  nodes,  seldom  branched. 

Culms  ascending,  often  prominently  geniculate,  slightly  compressed,  and 
grooved  or  flattened  above  each  sheath,  smooth,  often  branching  below,  15  to  20 
inches  tall. 

Leaves  of  sterile  culms  rather  numerous,  with  flat  or  slightly  involute  blades 
3  to  6  inches  long;  of  stem  3  or  4;  sheath  1  to  2  lines  wide,  4  to  7  inches  long; 
ligule  a  spreading  tuft  of  fine  white  hairs  1-j  lines  long. 

Inflorescence  a  rather  loose,  oblong  panicle,  5  to  7  inches  long;  rachis  angular, 
somewhat  flexuous.  branches  1,  2,  or  3  in  a  place,  2  to  4  inches  long,  with  few  or  no 
hairs  at  the  axis,  bearing  12  to  20  appressed  spikelets  on  angular,  twisted,  hispid 
pedicels  of  varying  lengths. 

Spikelets  linear-lanceolate,  5-  to  10-flowered,  2  to  3£  lines  long;  internodes  of 
slender  rachilla  £  line  long;  first  glume  ovate,  acute,  minutely  hispid  on  back 
above,  1-nerved,  £  line  long;  second  glume  same  as  first  but  nearly  twice  as  large; 
floral  glumes  broadly  ovate,  acutish,  convex,  scarious,  3-nerved,  f  to  nearly  1  line 
long;  palet  linear-oblong,  minutely  pubescent  on  the  2  nerves,  f  line  long,  arched, 
remaining  on  the  rachilla  after  the  seed  falls  with  the  floral  glume. 

Grain  amber  colored,  oblong,  £  line  long. 

PLATE  XLIX;  a,  spikelet  with  pedicel;  6,  empty  glumes;  &',  and  b",  apexes 
of  empty  glumes;  c,  floral  glume,  dorsal  and  side  view;  d,  palet. 

Texas  to  Arizona  and  Mexico.  In  the  Northern  States  this  species  seems  to 
be  confused  with  Eragrostis  pilosa. 


\ 


|v 

r          N 


ERAGROSTIS    PURSHII, 


No.  50. 

ELYMUS    SITANION    Schultes.      (Sitanion  elymoides  Raf.     Polyanthrix 

Hystrix  Nees.) 

Plant  annual,  or  short-lived  perennial,  from  rather  bulbous  base. 

Culms  tufted  at  base  with  many  radical  shoots,  erect,  unbranched,  terete,  hol- 
low, nearly  smooth,-  6  to  18  inches  tall. 

Radical  leaves  mostly  membranaceous  scales,  or  leafless  sheaths,  those  from 
radical  shoots  numerous,  striate,  often  pubescent,  or  nearly  glabrous  on  sheaths 
and  blades  below;  blade  flat  or  slightly  involute,  rigid,  hispid  above,  H  lines  wide, 
4  to  6  inches  long;  leaves  of  culm  3,  rarely  4;  sheaths  longer  than  internodes; 
blades  like  those  of  radical  shoots,  ligule  an  inconspicuous,  narrow,  membrana- 
ceous line,  often  auriculate  on  one  or  both  sides. 

Inflorescence  a  rather  loose  spike  2  to  3  inches  long;  rachis  articulate  at  base 
of  each  flattened  internode,  and  easily  separating. 

Spikelets  2  at  each  node  of  the  rachis,  nearly  sessile,  lanceolate,  5  to  6  lines 
long,  not  including  the  awns,  1-  to  5-flowered;  upper  flowers  sterile;  first  and  sec- 
ond glumes  nearly  equal,  side  by  side  in  front  of  the  spikelet,  narrow,  2-nerved  at 
base,  terminating  in  a  divergent  hispid  awn  2  to  4  inches  long;  floral  glumes  ovate- 
lanceolate,  acute,  round  on  back,  enveloping  seed  and  palet,  finely  scabrous,  indis- 
tinctly 5-nerved,  terminating  in  a  hispid  awn  2  to  2%  inches  long,  the  upper 
imperfect  glumes  short-awned^  palet  lance-linear,  obtuse,  hispid  on  the  two  nerves, 
margins  reflexed,  flat,  one-half  line  wide,  folded.  4  to  4^  lines  long. 

Grain  dull  brown,  linear,  wrinkled  lengthwise,  2%  lines  long,  adherent  to  palet 
and  enveloping  glume. 

Extensively  diffused  over  the  arid  and  desert  districts  of  the  West,  from  the 
Missouri  to  the  Pacific,  and  from  Dakota  to  Texas,  presenting  great  diversity  of 
size  and  appearance.  Sometimes  the  empty  glumes  are  divided  into  three  parts. 

PLATE  L;  a,  spikelet;  6,  floral  glume;  c,  palet. 


ELYMUS    S1TA~NIQJ1 , 


CORRECTIONS  AND  EMENDATIONS. 

I. 


No.  5.  Setaria  caudata,  second  line,  Plant  annual.  The  drawing  represents  a 
perennial  form  or  species  common  in  western  Texas,  Arizona,  New  Mexico,  and 
northern  Mexico.  There  is,  however,  a  closely  related  form  which  is  annual. 

No.  11.  Hilaria  mutica  Benth.  It  should  be  stated  that  this  is  Pleuraphis 
mutica  Buckley.  Mr.  Bentham  united  the  genus  with  Hilaria,  and  according  to 
the  views  of  some  botanists  Buckley's  name  should  follow  the  species  in  paren- 
theses; thus,  Hilaria  mutica  (Buckley)  Bentham. 

No.  15.  Elionurus,  plate  15.  The  specific  name  at  the  bottom  of  ..the  plate 
should  be  barbiculmis. 

Plate  19.  Andropogon  hirtiflorus  Kth.  The  figures  a  and  6  do  not  well  repre- 
sent the  glumes  of  the  species.  It  is  probable  that  by  mistake  the  drawings  were 
made  from  spikelets  of  A.  scoparius.  The  first  empty  glume  should  be  represented 
as  narrow  and  acuminate  at  apex,  with  the  back  scabrous-roughened  and  hairy. 

Plate  23.  Aristida  divaricata  H.  B.  K.  This  is  Aristida  Humboldtiana  Trin. 
Trinius  excludes  A.  divaricata  as  a  mixed  and  uncertain  species. 

Plate  27.  Epicampes  macroura  Kth.  I  was  misled  by  the  specimen  in  the 
United  States  Herbarium  (No.  1973  C.  Wright's  New  Mexican  Coll.)  in  naming 
this  species.  Evidently  it  is  not  E.  macroura  Kth.,  which  has  a  dense,  cylindrical 
spicate  panicle.  It  is  Epicampes  ligulata  Scrib.  Fournier  in  Enumeratio  Mexi- 
canarum  Plantarum  enumerates  13  Mexican  species  of  Epicampes,  of  which  we 
have  too  little  representation  to  determine  if  our  plant  is  among  the  number. 

Plate  28.  This  is  the  Cinna  macroura  of  Thurber  in  the  Botany  of  California, 
but  not  of  Kth. 

Plate  29.  Chloris  elegans  H.  B.  K.  is  believed  to  be  a  synonym. 

Plate  32.  This  is  Eustachys  glauca  Chap.  That  genus  being  now  united  to 
Chloris,  it  becomes  C.  glauca  (Chap.  )  Vasey. 

Plate  45.  Bouteloua  stricta.  It  should  have  been  stated  that  this  species  was 
collected  by  G-.  C.  Nealley  in  western  Texas. 

Plate  47.  The  figures  1  and  2  in  the  plate  should  be  transposed,  No.  1  being 
the  female  plant,  No.  2  the  male  plant. 

Plate  48.  Eremochloe.  This  name,  or  one  too  close  to  it,  viz,  Eremochloa 
Buse,  is  one  of  earlier  date  for  a  different  genus;  and  Professor  Hackel  has  named 
our  plant  Blepliaridachne. 


CORRECTIONS  AND  EMENDATIONS. 

II. 


Plate    2.  Add  after  the  name  (Thurber). 

Plate  14.  Transpose  the  numbers  1  and  2  of  the  plate. 

Plate  30.  Karwinskiana  should  be  Karwinskianus. 

Plate  33.  Albesceus  should  be  albescens. 

Plate  38.  The  name  on  the  plate  should  read  Triodia  stricta  (Torr.)  Vasey;  it 
was  Tricuspis  stricta  Torr. 

Plate  40.  The  name  should  'read  Triodia  trinerviglumis  (Munro).  It  was 
Tricuspis  trinerviglumis  Munro,  the  genus  being  united  to  Triodia  by  Mr. 
Bentham. 

Plate  42.  In  like  manner  the  name  here  should  be  DiplacJine  imbricata 
(Thurb.),  as  it  was  Leptochloa  imbricata  Thurb.  in  Bot.  California. 

Plate  43.  Strike  out  the  letter  s  in  Reverschoni. 

Plate  44.  The  name  should  read  Diplachne  rigida  (Munro)  Vasey.  It  was 
Leptochloa  rigida  Munro. 

Plate  46.  Add  Buckl.  after  the  name. 


U.  S.  DEPARTMENT  OF  AGRICULTURE. 

DIVISION  OF  BOTANY. 


ILLUSTRATIONS  OF  NORTH  AMERICAN  GRASSES. 

VOL      I. 


GRASSES  OF  THE  SOUTHWEST. 


PLATES  AND  DESCRIPTIONS 


GRASSES  OF  THE  DESERT  REGION  OF  WESTERN  TEXAS,  NEW  MEXICO, 
ARIZONA,  AND  SOUTHERN  CALIFORNIA. 


By  DR.  GEO.  VASEY, 

BOTANIST,  DEPARTMENT  OF  AGRICULTURE. 


PUBLISHED  BY  AUTHORITY  OF  THE  SECRETARY  OF  AGRICULTURE. 


WASHINGTON : 

GOVERNMENT   PRINTING  OFFICE. 
1891. 


LETTER  OF  TRANSMITTAL. 


WASHINGTON,  September,  1891. 

SIR:  I  have  the  honor  of  presenting  for  publication  the  first  volume  of  the  pro- 
posed work  called  "Illustrations  of  North  American  Grasses,"  which  have  been 
issued  as  Bulletin  No.  12,  parts  I  and  II;  and  it  is  proposed  to  follow  this  with  a 
second  volume  of  plates  and  descriptions  of  the  "  Grasses  of  the  Pacific  Coast." 
Respectfully, 

GEO.  VASEY, 

Botanist. 
Hon.  J.  M.  RUSK, 

Secretary  of  Agriculture. 


GENERAL  INDEX  OF  PLATES. 


Part.   Plate. 


^gopogon  geminiflorus     

I 

12 

Andropogon  cirrhatus  

I 

18 

hirtiflorus  

I 

19 

saccharoides  

I 

20 

Wrightii  

I 

21 

Aristida  Arizonica  

I 

22 

divaricata  

I 

23 

purpurea  

II 

7 

Bouteloua.  arenosa  

I 

34 

aristidoides  

I 

35 

Burkei  

I 

36 

eriopoda  

I 

37 

Havardii  

I 

38 

hirsuta  

I 

39 

Humboldtiana  

I 

40 

oligostachya  

I 

41 

prostrata  

I 

42 

racemosa  ,  

I 

43 

ramosa  

I 

44 

Bouteloua  stricta  

I 

45 

trifida  

I 

46 

Buchloe  dactyloides  

I 

47 

Cathestecum  erectum  

I 

13 

Geuclirus  nivosuroides  

I 

6 

tribuloides  

I 

7 

Chloris  alba  

I 

29 

ciliata  

I 

30 

cucullata  

I 

31 

glauca   

I 

32 

Swartziana  

II 

23 

verticillata  

I 

33 

Cottea  pappophoroides  

II 

29 

Diplachne  f  ascicularis  

II 

41 

imbricata  

II 

42 

Reverchoni  

II 

43 

rigida  

II 

44 

viscida  

II 

45 

Elionurus  barbiculmis  

I 

15 

tripsacoides  , 

II 

1 

Elymus  Sitanion  

II 

50 

Epicampes  macroura  

I 

27 

rigens  

I 

28 

Eragrostis  curtipedicellata  

II 

46 

lugens  

II 

47 

oxylepis  

II 

48 

Purshii  

II 

49 

Kivinochloe  Bigelovii  '.  

I 

48 

Kingii  

I 

48 

Eriochloa  sericea  

I 

1 

Part.    Plate. 

Heteropogon  contortus I  16 

Hilaria  cenchroides I  10 

mutica I  H 

rigida II  2 

Lycurus  phleoides J,'...    ...  II  15 

Melica  diffusa I  49 

Porteri '. I  5() 

Miihlenbergia  Buckleyana II  12 

depauperata II  14 

distichophylla I  25 

gracilis I  26 

Neo-Mexicana II  13 

Schaffneri II  14 

Munroa  squarrosa II  31 

Oryzopsis  fimbriata II  11 

membranacea II  10 

Panicum  hulbosum    I  2 

ciliatissirnum I  3 

lachnanthum I  4 

Paspalum  distichurn II  3 

lividum II  4 

pubifl6rum II  5 

Phalaris  intermedia,  var.  angusta II  6 

Pappophorum  apertum II  17 

Wrightii II  28 

Schedonnardus  Texanus II  24 

Scleropogoii  Karwinskianus II  30 

Setaria  caudata I  5 

Sporobolus  argutus II  16 

Buckleyi II  17 

interruptus II  18 

tricholepis II  19 

Wrightii II  20 

Stenotaphrum  Americanum I  8 

Stipa  flexuosa I  24 

pennata II  8 

Scribneri II  19 

Thurberia  Arkansana I  9 

Trachypogon  polymorphic I  17 

Tragus  racemosus I  14 

Trichloris  pluriflora II  24 

verticillata II  25 

Triodia  acuminata .' II  32 

albescens II  33 

eragrostoides II  34 

grandiflora II  35 

Nealleyi '. . '. II  36 

pulchella II  37 

stricta II  38 

Texana    II  39 

trinerviglumis II  40 

Trisetum  Hallii II  21 

interruptum II  22 


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